air bag technology in light passenger vehicles

AIR BAG TECHNOLOGYIN LIGHT PASSENGER

VEHICLES

Prepared By The

OFFICE OF RESEARCH AND DEVELOPMENTNational Highway Traffic Safety Administration

JOHN HINCH

WILLIAM T. HOLLOWELL

JOSEPH KANIANTHRA

WILLIAM D EVANS

TERRY KLEIN

ANDERS LONGTHORNE

SABRINA RATCHFORD

JOHN MORRIS (RAINBOW TECHNOLOGY, INC.)RAJESH SUBRAMANIAN (RAINBOW TECHNOLOGY, INC.)

JUNE 27, 2001REVISION 2

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Table of Contents

Sec Title Page Number

List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii

List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

Executive Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ES-1

1.0 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

2.0 Discussion of Advanced Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

3.0 Analysis of Air Bag System Trends by Model Year and Air Bag Inflator Power Characteristics . . . 9

3.1 Trend Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93.2 Tank Test Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123.3 Driver Air Bag Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143.4 Introduction of Passenger Air Bags in Fleet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203.5 Passenger Air Bag Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

4.0 Air Bag Performance in Late Model Passenger Vehicles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264.1 NHTSA’s Out-of Position Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

4.1.1 Driver Air Bag Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264.1.2 Passenger Air Bag Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284.1.3 Two-Stage Air Bag Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294.1.4 Distance From the Air Bag Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

4.2 Performance of New Model Vehicles with Redesigned Air Bag Systems in Rigid Barrier Tests 32

5.0 Discussion of Evolving Air Bag Fatality Trends Using SCI Data . . . . . . . . . . . . . . . . . . . . . . . . . 34

6.0 Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Appendix A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

Appendix B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

Appendix C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1

Appendix D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1

Appendix E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-1

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List of Tables

Num Title Page Number

Table 1. Occupant Protection Technology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Table 2. Trend Data for Weighted Average Adjusted Driver Air Bag Inflator Peak Pressure and RiseRate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Table 3. Trend Data for Weighted Average Adjusted Passenger Air Bag Inflator Peak Pressure andRise Rate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Table 4. Neck Injury Data for Out-of-Position Testing for Position 1, by Model Year. . . . . . . . . . . . . 27Table 5. Neck Injury Data for Out-of-Position Testing for Position 2, by Model Year. . . . . . . . . . . . . 27

Table 6. Neck Injury Reference Values for Acura RL Dual Stage Testing with Out-of-Position DummyPlacement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

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List of Figures

Fig Num Title Page Number

Figure 1. Illustrative Tank Test Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Figure 2. Weighted Average Air Bag Volume for IR Fleet by Model Year, Driver Side. . . . . . . . . . . 13

Figure 3. Weighted Average Air Bag Volume for IR Fleet, by Model Year, Passenger Side. . . . . . . 14

Figure 4. Weighted Average Adjusted Driver Air Bag Inflator Peak Pressure by Model Year.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Figure 5. Weighted Average Adjusted Driver Air Bag Inflator Rise Rate, by Model Year. . . . . . . . . 15

Figure 6. Weighted Average Adjusted Driver Air Bag Inflator Data. . . . . . . . . . . . . . . . . . . . . . . . . 16

Figure 7 Graphical Representation of Weighted Average Adjusted Driver Air Bag Inflator Output for IRFleet Comparing MY 1997 to MY 1998. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Figure 8. Adjusted Driver Air Bag Inflator Characteristics, by Direction of Change in Rise Rate andPeak Pressure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Figure 9. Frequency Distribution Plot showing Concentration Areas for Rise Rate and Peak Pressure,Adjusted Driver Air Bag Inflator Output, MY 1997. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Figure 10. Frequency Distribution Plot showing Concentration Areas for Rise Rate and Peak Pressure,Adjusted Driver Air Bag Inflator Output, MY 1998. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Figure 11. Vehicles in the IR Fleet with Driver or Passenger Air Bags, by Model Year. . . . . . . . . . . 20

Figure 12. LTVs in the IR Fleet with Passenger Air Bags, by Model Year. . . . . . . . . . . . . . . . . . . . 21

Figure 13. Weighted Average Adjusted Passenger Air Bag Inflator Peak Pressure, by Model Year. . 22Figure 14. Weighted Average Adjusted Passenger Air Bag Inflator Rise Rate, by Model Year.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figure 15. Weighted Average Adjusted Passenger Air Bag Inflator Data. . . . . . . . . . . . . . . . . . . . . 23

Figure 16. Graphical Representation of Average Adjusted Passenger Air Bag Inflator Output for IRFleet Comparing MY 1997 to MY 1998. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Figure 17. Adjusted Passenger-Side Air Bag Inflator Characteristics, by Direction of Change in RiseRate and Peak Pressure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Figure 18. Frequency Distribution Plot showing Concentration Areas for Average Rise Rate and PeakPressure, Adjusted Passenger Air Bag Inflator Output, MY 1997. . . . . . . . . . . . . . . . . . . . . . . . . 25

Figure 19. Frequency Distribution Plot showing Concentration Areas for Average Rise Rate and PeakPressure, Adjusted Passenger Air Bag Inflator Output, MY 1998. . . . . . . . . . . . . . . . . . . . . . . . . 26

Figure 20. Average Test Results for Neck Injury Measurements for Driver Out-of-Position Testingwith 5th Percentile Female Dummy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

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Figure 21. Average Normalized Injury Criteria for Passenger Out-of-Position Testing with 6-Year-OldChild Dummy–Position 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 22. Average Normalized HIC 15 msec for Passenger Out-of-Position Testing with 6-Year-OldChild Dummy–Position 1 at Various Clearances. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Figure 23. Average Normalized Neck Criteria for Passenger Out-of-Position Testing with 6-Year-OldChild Dummy–Position 1 at Various Clearances. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Figure 24. Average Normalized Chest Acceleration for Passenger Out-of-Position Testing with 6-Year-Old Child Dummy–Position 1 at Various Clearances. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Figure 25. Average Normalized Chest Deflection for Passenger Out-of-Position Testing with 6-Year-Old Child Dummy–Position 1 at Various Clearances. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Figure 26. Driver Normalized Injury Measures in 30 mph Unbelted Barrier Tests. . . . . . . . . . . . . . . 33

Figure 27. Right Front Passenger Normalized Injury Measures in 30 mph Unbelted Barrier Tests. . . 34

Figure 28. SCI Data for Fatal Drivers Normalized for Registrations of Vehicles with Driver Air Bags,by 12 Month Interval. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Figure 29. SCI Data for Fatal Passengers Normalized for Registrations of Vehicles with Passenger AirBags, by 12 Month Interval. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Figure 30. SCI Data for Fatal Drivers Normalized for Vehicle Registrations, by Model Year.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Figure 31. SCI Data for Fatal Passengers Normalized for Vehicle Registrations, by Model Year.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

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Executive Summary

In December 1997, the National Highway Traffic Safety Administration (NHTSA) sent an informationrequest to nine automobile manufacturers requesting detailed technical information on the currentindustry practice on air bag technologies, and how air bag design and performance characteristics hadevolved through the 1990's. The manufacturers provided the agency with the requested data, much ofwhich was proprietary and confidential. The data included information on MY 1990 through MY 1998vehicles.

This report uses those data, as well as other available information, to illustrate the general trends in airbag design and performance characteristics. It also uses data from static and dynamic tests of variousair bags and an assessment of air bag performance in terms of injury measures made on dummiesrepresenting occupants under low speed and high speed conditions. It also discusses the results ofinvestigations of real world crashes by NHTSA’s Special Crash Investigations office. The report isonly intended to provide an overview of the trends in air bag characteristics and design changes. Thelimited analyses presented in this report are not intended to be a comprehensive report on the projectedsafety performance of the past, present, or future vehicle fleet.

Section 1 of the report gives the background which led to the information request. Section 2 providesa summary of various advanced air-bag related technologies that are actively being considered by themanufacturers. Additionally, a brief description of air bag design changes and air bag performancemeasures are given for both driver and passenger air bags. Section 3 discusses general trends,including a detailed analysis of inflator output trends over time. Section 4 gives a discussion of the staticand dynamic test results from air bag aggressivity and vehicle crash tests conducted by the agency. Section 5 provides a discussion of the trends in real world fatalities due to air bags. Section 6 gives asummary of the findings.

The agency’s analyses of the data show some of the ways in which air bag technology is evolving. There have been numerous changes in air bag design both on the driver side and the passenger side.

Some of the changes in air bag design reduce their aggressivity, an issue to which NHTSA has given agreat deal of attention. Since the problem of air bag deaths first emerged, NHTSA has taken a numberof steps to address the problem. In late November 1996, the agency announced that it would beimplementing a comprehensive plan of rulemaking and other actions (e.g., consumer education)addressing the adverse effects of air bags. Recognizing that a relatively long period of lead time isrequired to make some types of significant design changes to air bags, the agency's comprehensive plancalled for both interim and longer-term solutions. The interim solutions included temporary adjustmentsin Standard No. 208's performance requirements to ensure that the vehicle manufacturers hadmaximum flexibility to address quickly the risks from air bags. One such change was to permitmanufacturers to certify their vehicles to an unbelted sled test option instead of the unbelted 30 mph

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rigid barrier test. This facilitated efforts of the manufacturers to make quick design changes to their airbags, such as reducing inflator power.

Data provided by the manufacturers show that air bag outputs have been reduced significantly in themost recent model year (MY) vehicles in comparison to the earlier generation vehicles. While there aremany means by which air bag aggressivity can be reduced, reducing air bag outputs is a quick means ofaccomplishing this goal. The agency’s analyses also show that, between MY 1997 and MY 1998, 50to 60 percent of the vehicles in the fleet covered by the information request lowered the output of thedriver-side air bag, while about 50 percent of the fleet lowered the output for the passenger side. Comparison of the data for MY 1997 and MY 1998 vehicles show that, on average, the pressure riserate in MY 1998 vehicles decreased about 22 percent for the driver air bag and 14 percent for thepassenger air bags.

The data provided by the manufacturers also show that they have made significant changes in the designof their air bag systems other than the air bag pressure rise rate and peak pressure in their air bagdesigns, some over a period of many years. One change is the recessing of driver air bags so that themodule is located farther away from the plane of the steering wheel, and thus farther from the driver. Although this practice was not common in the early 90's, it is found in almost half of the MY 1997 andMY 1998 vehicles. Similarly, the air bag mounting location on the passenger side has also shownsignificant changes. Other features, such as cover tear patterns, tear pressure, fold patterns and thenumber and type of tethers have changed in recent years, all of which may have collectively contributedto reduced aggressivity of air bags.

NHTSA conducted tests on the aggressivity of air bags in certain MY 1996, MY 1998 and MY 1999vehicles. Static tests were conducted with 5th percentile female dummies in the driver seating positionand 6-year-old dummies in the passenger seating position, placed in two positions in close proximity ofthe air bag. Various dummy injury measures, such as the Head Injury Criteria (HIC), chestaccelerations, chest deflections, and neck injury measures were obtained. These results showed thatthe air bags in MY 1998 and 1999 vehicles, generally, posed less of an injury risk to out-of-positionoccupants than the air bags in the MY 1996 vehicles. However, it should be noted that, for each modelyear, only a few vehicles were tested. While NHTSA attempted to select vehicles that wererepresentative of the existing fleet, firm conclusions can only be reached after testing additional vehicles.

NHTSA has conducted special crash investigations to assess whether there has been a reduction in therate of air bag-induced fatalities for later MY vehicles. While there has been little change in the driverair bag fatality rate between MY 1992 and MY 1997 vehicles, there has been a significant reduction infatality rate in MY 1998 vehicles and no driver air bag fatalities, thus far, in MY 1999 vehicles. Therehas also been reduction in passenger fatality rate in recent MY vehicles, with MY 1998 showing anappreciable reduction.

One concern about reducing inflator power is potential loss of protection in high severity crashes. Tohelp see how vehicles certified to the unbelted sled test perform in high severity crashes, NHTSA tested

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13 production vehicles from MY 1998-1999, in a 30 mph barrier test using unbelted 50th percentiledummies in the driver and passenger seating positions. For the driver dummy, except for the femurloads for one vehicle, the injury measures for the femurs, chest (accelerations and displacements), head,and neck were below the requirements specified in FMVSS No. 208, with most below 80 percent ofthe threshold values. For the passenger seating position in one vehicle, the chest acceleration slightlyexceeded the FMVSS No. 208 requirement. All the other injury measures met the requirements inFMVSS No. 208. Again, most were below 80 percent of those requirements. Thus, with minorexceptions, the tested vehicles, although certified to the sled test, also passed the pre-existing 30 mphunbelted rigid barrier crash test.

Some advanced technologies are already in some vehicles and are expected to be used in additionalvehicles in the early 2000's model years, as a result of NHTSA’s ongoing rulemaking to requireadvanced air bags. Some of the technologies identified extend from changes in inflator characteristics,new air bag shapes, sizes, fabrics, venting systems and venting levels, occupant size and locationsensors, seat position sensors, belt use sensors, and crash severity sensors to computation algorithmsthat use the information in making air bag deployment decisions.

In conclusion, risks to out-of-position occupants have been reduced in recent years. These reducedrisks can be ascribed, at least in part, to the following:

• On average, the inflator outputs of recently redesigned air bags have been significantly reduced. While there are variations among manufacturers and among vehicles of each manufacturer,analysis of the data provided by the manufacturers show a significant reduction in the averagepeak pressure and pressure rise rate of MY 1998 air bags in comparison to earlier air bags. However, those parameters increased in approximately ten percent of the vehicles covered bythe information request and approximately one third showed no change.

• Changes in air bag volumes, vent sizes, inflator characteristics and other design changes have allcontributed to a reduction in the safety risk from air bags, which is reflected in the dummy injurymeasures obtained from static deployment of air bags of various model years as well as in realworld crash investigations.

• Based on static and dynamic tests using adult and child dummies and the injury measuresobtained in those tests, it is clear that air bags in recent MY 1998 and 1999 vehicles are lessaggressive than the pre-MY 1998 air bags. As such, these air bags generally pose less of aninjury risk to out-of-position occupants. The special crash investigations of real-world casestend to confirm this general trend showing a significant reduction in fatality rates due to air bagsin recent MY vehicles.

• In high speed rigid barrier tests at 30 mph of seven MY 1998 and six MY 1999 vehicles,unbelted, 50th percentile male dummies were used in the driver and passenger seating positions.The dummy injury measures for the 50th percentile male driver dummy showed that the HIC,

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chest “g,” chest deflection and the neck injury measures (Nij) were all within the thresholdvalues. In a MY 1999 vehicle, the femur load exceeded the limit. For the passenger dummy,the chest “g” value exceeded the limit by 1.4 “g” in one vehicle and all others met therequirements.

• Manufacturers have made many changes to air bag designs. They are also on the threshold ofmaking a significant leap in introduction of sophisticated technologies to improve air bagperformance. For example, tailored inflation to suit different size occupants located in variouspositions in relation to the air bag and to match the severity of the crash will be a reality in thenot too distant future. NHTSA’s ongoing rulemaking to require advanced air bags will ensurethat future air bags provide improved protection of belted as well as unbelted occupants ofdifferent sizes in moderate to high speed crashes, while minimizing risks posed by air bags toinfants, children, and other occupants, especially in low speed crashes.

1 The manufacturers were: Chrysler, Ford, General Motors, Honda, Mercedes-Benz, Nissan,Toyota, Volkswagen and Volvo. The vehicles which are covered by their responses will be called the“IR Fleet.”

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1.0 Introduction

On December 17, 1997, the Associate Administrator for Safety Performance Standards of theNational Highway Traffic Safety Administration (NHTSA) sent a letter to nine vehicle manufacturers1

requesting detailed technical information about the frontal crash protection systems of vehicles that theyhad designed, built, and sold during model years 1990-1998. Over time, numerous design andperformance changes have been made by vehicle manufacturers to their vehicles’ frontal crashprotection systems to both mitigate the risk to occupants and improve the performance of thesesystems. These occupant protection systems included air bags, safety belts, crash sensors, steeringsystem components such as steering wheels and steering column, knee bolsters, dash boards, and thevehicle structures on which they were mounted. The primary purpose of the information request was toprovide NHTSA with specific technical information documenting these changes over time. Amongother things, the agency wanted to understand the specific changes made in occupant restraint designsubsequent to its March 19, 1997, final rule that allowed manufacturers to temporarily certify theirvehicles to Federal Motor Vehicle Safety Standard (FMVSS) No. 208 using a sled test instead of arigid barrier test.

Pursuant to the Intermodal Surface Transportation Efficiency Act of 1991, passenger cars and lighttrucks are required to have air bags at the driver position and the right front passenger position. As ofSeptember 1, 1999, NHTSA estimates that air bags have saved over 4,600 lives. However, in theearly 1990's, fatalities and serious injuries caused by air bags began to occur. In November, 1996,NHTSA announced a comprehensive plan in response to public concerns related to occupants,especially children who are out-of-position, being injured or killed by deploying air bags. At the timethe information request was made, NHTSA had completed or was working on three rulemakinginitiatives that the agency believed would minimize occupant injury risks due to deploying air bags whilepreserving the benefits of the occupant protection system.

On March 19, 1997, NHTSA implemented the first step in this plan by facilitating efforts of vehiclemanufacturers to quickly redesign these air bags by certifying their vehicles to FMVSS No. 208 using asled test with a generic crash pulse instead of a rigid barrier test. This action resulted in air bags in mostMY 1998 vehicles being redesigned, with most having reduced inflator output and aggressivity.

Beyond the concerns with the early and current generation air bags, the agency continued to take stepsin regards to future air bags. The enactment of the Transportation Equity Act for the 21st Century(TEA 21) on June 9, 1998, required NHTSA to initiate new rulemaking on air bags. On September17, 1998, the agency published a new proposal to amend FMVSS No. 208 to require advanced airbags. The goal of this proposal was to improve occupant protection for occupants of different sizes,regardless of whether they use their seat belts, while minimizing the risk to infants, children, and otheroccupants of deaths and injuries caused by air bags. The proposal gave automakers the maximum

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flexibility to pursue effective technological solutions. The proposal incorporates additional air bagsystem performance tests and requirements to increase protection for properly seated adults, and togreatly reduce air bag deployment risks for infants, young children and small adults.

Our comprehensive plan provided for a rapid change in air bag designs, a method for occupants at highrisk to obtain on-off switches for air bags in their present vehicles, and a proposal to improve air bagperformance in future vehicles.

These rapid changes gave rise to two questions. First, what technological advances have actually beenincorporated in automobile designs by vehicle manufacturers to enhance safety in frontal crashes? Secondly, how do those changes affect occupant safety, especially as the risk to occupants from airbags became better understood?

The December 17, 1997 information request (IR) was intended to address these questions. First, theagency needed to identify the technical changes being made in motor vehicles for frontal crashprotection. By identifying those design changes, the agency could determine whether changes in injuryand fatality patterns in frontal crashes correlated to the changes in air bag design and other vehiclecharacteristics. This could allow the agency to identify the most significant performance characteristicsof an occupant restraint system, and the vehicle designs that achieved the best safety performance.

The analysis in this report aggregates the data obtained from the manufacturers to avoid disclosingconfidential information.

2.0 Discussion of Advanced Technology

As part of the IR, NHTSA requested information on advanced technology. Based on a review of themanufacturers’ responses, the types of advanced occupant protection technologies introduced by thesenine manufacturers are presented in Table 1. Also included are advances and improvements intechnologies that were used in the design and development of their early air bag systems. Since othermanufacturers who were not sent the IR were also producing motor vehicles at the same time, it is quitepossible that those manufacturers also developed and introduced other technologies during the sametime period. Further, there may be additional safety systems introduced by manufacturers which werenot identified during the IR process. A discussion of new technologies which post-date the IRresponses is also presented in the table.

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Table 1. Occupant Protection Technology.

Technology Description of Technology Based on the IR response Discussion of Activitieswhich Post-Date the IR

Buckle Sensors Sensors that sense if the occupant is wearing theseat belt. For use in systems with dual level airbag inflation thresholds, permitting a differentlevel of deployment crash velocity for belted andunbelted occupants.

Mercedes had buckle sensors on all model yearsMY 1990-98. This represents about one percent ofthe IR fleet.

Honda installed these devicesin MY 1999. Othermanufacturers are currentlyimplementing these sensorsfor MY 2000. Future use ofthe buckle sensor will allowdifferent inflation levels forbelted and unbelted occupants(i.e., low level for belted andhigh level for unbelted).

Pre Tensioners A device, usually pyrotechnic, to remove slackfrom the seat belt upon detection of a crashcondition.

Driver: Mercedes, Volkswagen & Volvo in MY 1990,Honda in MY 1991, Nissan & Toyota in MY 1993,Chrysler in MY 1996, GM in MY 1997.Passenger: Mercedes in MY 1990, Honda inMY 1991, Volkswagen in MY 1992, Toyota, Nissan& Volvo in MY 1993, GM in MY 1997.

Load Limiters A device to limit the forces imparted to theoccupant by the seat belt during the crash event. The forces are prevented from exceeding apredetermined level by allowing the seat beltwebbing to yield when the forces reach this level.

Driver: Toyota introduced it in MY 1990, Chrysler &GM in MY 1991, Ford & Honda in MY 1993,Mercedes in MY 1996, Nissan, Volkswagen & Volvoin MY 1998.Passenger: Chrysler, Ford, Gm, Honda & Toyota inMY 1994, Mercedes in MY 1996, Nissan,Volkswagen & Volvo in MY 1998.

Web Clamps A device in the seat belt retractor that locks thewebbing to prevent or minimize shoulder beltspool-out.

Driver: GM, Honda & Nissan in MY 1990, Ford inMY 1991, Chrysler in MY 1992, MY Toyota inMY 1993, GM in MY 1997.Passenger: Honda in MY 1991, Chrysler inMY 1993, Ford, Nissan & Toyota in MY 1994, GM inMY 1997.



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Advanced CrashSensing

Sensors that discriminate crash severity. Foruse with systems utilizing staged air baginflation. Also used in dual threshold air bagsystems.

Information on this technology was not requested inthe IR.

Several Manufacturers willsoon be adding this technologywhich will discriminate crashesbased on crash severity.

Multi StageInflation

A multi staged air bag system is a system thatcan control two or more air bag inflation stagesindependently to optimize occupant protection,i.e., a low stage for a small occupant and a highstage for a larger person.

None reported Honda installed multi stageinflators on passenger side inMY 1999. Othermanufacturers will be usingthis technology beginning inMY 2000.

On/off Switch A switch to deactivate the passenger air bag. For use when children can only be transported inthe front seat, such as in pickup trucks, or whenthere is not sufficient room to put a child seat inthe back seat.

GM: C/K, S-10 and Sonoma trucks in MY 1997-98models; FORD: F-series trucks, Ranger & Mazda B-Series in MY 1997-98 models; CHRYSLER: DodgeDakota, Ram Pickups in MY 1998.

Child SeatSensors(Tags)

Sensors that sense if a child seat is occupyingthe front passenger seat. For use in systemswhere the passenger air bag is designed not todeploy or deploy with decreased force if a childseat is placed on the front passenger seat.

Mercedes introduced this in MY 1998.

Seat PositionSensors

Used to sense driver seat adjustment position. For use in systems where the air bag is designednot to deploy or deploy with decreased force ifthe seat is positioned in close proximity to the airbag.

No manufacturer reported using Seat PositionSensors in the IR fleet.

One manufacturer will installseat position sensors inMY 2000.

Weight/PatternRecognition TypeSensors

Sensors that sense if the front passenger seat isoccupied. Used to discriminate children and childseats from adults. For use in systems where thepassenger air bag is designed not to deploy ordeploy with decreased force if the frontpassenger seat is occupied by a child or a childrestraint.

No manufacturer reported using Weight Sensors inthe IR fleet.

Manufacturers will begininstalling weight/patternrecognition sensors inMY 2000. Wide use isexpected in the next modelyear or two.



5

CapacitanceSensors

Sensors utilizing an electrical field to determine ifthe front passenger seat is occupied and thelocation and size of the occupant. For use insystems where the passenger air bag is designedto not deploy or deploy with decreased force if achild or out of position occupant is occupying theseat.


Some may be in use, butresearch is ongoing.

Pre-crash Sensors A sensor that senses an impending crash andcould allow a crash severity sensor to make anearlier decision on whether or not to deploy the airbags. This could lead to reduced air bagdeployment force on the occupant.

No manufacturer reported using Pre-crash Sensorsin the IR fleet.

Research underway

Infrared Sensors Sensors utilizing heat detection to determine ifthe seat is occupied and the location and size ofthe occupant. For use in systems where the airbag is designed to not deploy or deploy withdecreased force if a child or out of positionoccupant is occupying the seat.


Under research and may beintroduced soon.

Inflatable KneeBolsters

Small cylindrical air bags located at the bottom ofthe instrument panel to reduce femur forcesduring the crash event.

No manufacturer reported using Inflatable KneeBoosters in the IR fleet.

Some manufacturers haveused these devices and othersare planning their use.

Hybrid Inflators Device used to generate the gas to inflate the airbag. Can be classified as pyrotechnic, hybrid orcompressed gas. The predominant driver andpassenger side inflators have been thepyrotechnic type.

DRIVER: In MY 1998 manufacturers introducedhybrid driver inflators. PASSENGER: In MY 1998 about 45 per cent of thepassenger side inflators were the hybrid type.

Crash Sensors Device used to sense an impending crash,generally electromechanical or electronic, or acombination of each (electronic-electromechanical). In the early 1990's the vastmajority of crash sensors were multipleelectromechanical (spring mass).

TRENDS: The trend is toward either a singleelectronic or a combination electronic-electromechanical sensor, 73 percent in MY 1998. Also in MY 1998, 44 percent of the vehicles in theIR fleet had only one crash sensor.



2 Mid mounted passenger air bags are mounted in the portion of the instrument panel facing the passenger, while top mounted passenger air bags aremounted in the top portion of the instrument panel, typically facing upward toward the windshield.

6

Tethers Internal straps used to control the shape of theair bag.

Driver: In the early 1990's the majority of the driverair bags had no tethers. In MY 1998, 88 percent ofall vehicles in the IR fleet had two or more driver airbag tethers.PASSENGER: The majority of passenger air bagsremain untethered.

Inflation Time Time from initiation of air bag inflation to full airbag inflation

TREND: The average time for driver air bag inflationhas been consistent since MY 1990, approximately33 ms. The average time for passenger air baginflation was 12 percent less in MY 1998 (52 ms)than MY 1993 (59 ms).

Area of Opening The area of the opening through which the air bagis deployed.

TREND: Although there has been a 19 percentreduction in air bag volume, the area of the driver airbag opening has remained constant. In contrast, thepassenger air bag opening has remained constantwhile its volume has decreased 27 percent onaverage.

Air BagDeploymentDistance

The average distance from the air bag module tothe maximum rearward point the air bag reaches,Distance A, and the average distance from theseating reference point (SRP) to the maximumrearward point the air bag reaches, Distance B.

DRIVER: Distance A has decreased approximatelyone inch since MY 1991 and Distance B has increased approximately three inches since 1991,placing the aft face of the deployed air bag furtherfrom the driver.PASSENGER: For mid mounted2 air bags DistanceA has decreased approximately 6 inches andDistance B increased about 9 inches placing the airbag further from the passenger. Distance A hasbeen constant for top mounted air bags.



7

Air Bag Volume DRIVER: The average volume of the driver air baghas remained constant since MY 1990(approximately 56 liters). PASSENGER: The average volume of thepassenger air bag was 27 percent smaller in 1998(120 liters) than it was in MY 1993 (165 liters).

Air BagMounting Location

The driver air bag can be either recessed, flush,or protruding from the steering wheel.The passenger air bag can be either top or midmounted on the passenger side of the instrumentpanel.

DRIVER: The trend has been toward an increase inrecessed driver air bags and a decrease inprotruding air bags.PASSENGER: The trend has been toward anincrease in mid mounted air bags and a decrease intop mounted air bags.

Tear Patterns The four predominant tear patterns for the driverair bag are the H, U, I, and horizontal. SeeAppendix A for description.The four predominant tear patterns for thepassenger air bag are the H, U, and horizontalplus a breakaway door. See Appendix A fordescription.

DRIVER: Predominantly an H shaped tear, thecurrent trend shows an increase in I and U shapedtear patterns and a decrease in the H shaped tearpattern.PASSENGER: Predominantly a horizontal shapedtear, the current trend shows the H shaped tearpattern increasing and the number of air bag modulecover doors decreasing.

MinimumBreakout Pressure

The minimum pressure required for the air bag tobreak through the air bag cover at the time ofdeployment

DRIVER: Since MY 1993 the average minimumbreakout pressure for the driver air bag hasdecreased 28 percent.PASSENGER: Since MY 1993 the averageminimum breakout pressure has decreased 24percent.



8

Fold Pattern The predominant driver air bag fold patterns arethe accordion, reverse roll, overlap, and modifiedaccordion. See Appendix A for a description.The predominant passenger air bag fold patternsare the accordion, roll, overlap, and rotatedaccordion. Again see Appendix A for adescription.

DRIVER: The reverse roll has been the predominantdriver air bag fold pattern since 1990. The number ofdriver air bags with overlap folds has increasedsince MY 1993. PASSENGER: The trend in passenger air bag foldshas been an increase in rotated accordion and rollfolds and a decrease in accordion folds.

9

3.0 Analysis of Air Bag System Trends by Model Year and Air BagInflator Power Characteristics

The manufacturers’ air bag systems data were analyzed to determine various trends. In order to usethese data, NHTSA compiled the data in an electronic file using a uniform format. During this review,NHTSA made several revisions to the input data, as a result of communications with the manufacturers.

Appendix A consists of analyses of the data submitted to NHTSA in response to the questions in theInformation Request (IR). This appendix presents a number of graphical representations of the datacontained in the IR computer file, in summary form. The data are presented by model year of vehicles,and weighted by the number of vehicles sold, as reported by R.L. Polk in the National VehiclePopulation Profile. It should be noted that in the early years presented in the graphs, not all vehicleswere equipped with air bags, especially passenger air bags. Therefore, changes over time (model year)do not necessarily represent changes in air bag characteristics, but may also represent introductions ofair bags, especially passenger air bags, into the fleet as new vehicles became equipped with these newsystems. The introduction to Appendix A provides a description of the types of information presentedon each page.

Data Collection Processes and Data DefinitionsNHTSA received the data related to air bag systems from manufacturers in response to the agency’sletters. The outgoing letter which lists the questions is presented in Appendix B. Throughout the reportand in responses to questions, several references are used to describe specific locations of certaincomponents within the vehicle. These definitions are also found in the outgoing letter.

NHTSA also informally requested electronic copies of each major submission which was utilized, alongwith the hard copy submission, to develop a computerized. standard format for the data. Throughoutthe analytical process, NHTSA communicated with the manufacturers to obtain clarifications andreplacement data where the submissions were ambiguous or erroneous.

Discussion of weightingManufacturers submitted data specific to each make/model/model year combination. NHTSA did notrequest sales data for each type of vehicle sold. The analysis used sales data obtained from R.L. Polk. These data were then used to weight each make/model/model year.

3.1 Trend Analysis

The following discussion is based on Appendix A. For further discussion, please refer to the appendix.

Driver Air Bag Location: Some manufacturers have changed the location of the driver air bag. FromMY 1990-1998, there has been an industry trend to recess the driver air bag into the steering column,with nearly 50 percent having the air bag recessed in MY 1998, up from about 10 percent in the earlyyears covered by the IR. This change has been relatively slight, with the average of all driver air bags inthe IR fleet being recessed about 0.2 inches below the plane of the steering wheel in MY 1998.

10

Passenger Air Bag Mounting Location: There has been a trend to move toward mid-mounted airbags, increasing from about 20 percent in MY 1990 to over 50 percent in MYs 1997 and 1998.

Direction of Movement of Air Bag Module: Analysis of whether the driver air bag module wasdesigned to move away from the occupant during deployment indicated that very few manufacturersemployed this technology, about 5 percent in MY 1998. A similar trend was observed on thepassenger side, but here about 15 percent of the modules were designed to move away from theoccupant in MY 1998.

Air Bag Module Opening Size: The size of the opening of the air bag module has decreased overthe years for driver air bags. The average opening size was about 40 square inches in MY 1990, anddecreased to about 33 square inches in MY 1998. On the passenger side, the average opening sizehas remained about constant, at about 70 square inches. Similar trends were observed for the air bagcover opening.

Breakout Pressure: Minimum breakout pressure on the driver side has decreased somewhat, froman average of about 41 psi in MY 1990 to 31 psi in MY 1998. On the passenger side the pressure hasdecreased from about 54 psi in MY 1993 to an average of about 38 psi in MY 1998.

Cover Mass: The average mass of the bag cover has remained nearly constant over the years - aboutseven ounces on the driver side and about 14 ounces on the passenger side.

Door Tear Pattern: There was an observable trend in the type of tear patterns on the driver side. “U” shaped and “I” shaped tear patterns have become more common in the last 5 years, accounting fornearly 40 percent in MY 1998. “Horizontal” tear patterns have remained about constant, while “H”shaped patterns have decreased markedly over the years. On the passenger side, the use of the “H”shaped tear has increased and the use of the “U” shape tear has decreased, while the others do notshow any clear indication of a trend.

Bag Fold Patterns: Fold patterns have remained fairly constant over the years on the driver side, witha slight increase in the “overlap” design. On the passenger side, there has been a slight decrease in the“accordion” type in favor of the “rotated accordion” type.

Air Bag Mass: The mass of the air bag itself has decreased slightly over the years on the driver side,going from an average of about ten ounces in MY 1990 to nine ounces in MY 1998. On the passengerside, it decreased from an average of about 22 ounces in MY 1993 to about 20 ounces in MY 1998.

Air Bag Inflation Time: The average amount of time required to inflate the air bag has been relativelyconstant over the years at 33 milliseconds for driver air bags. On the passenger side, it has also beenconstant for the past 5 years at 50 milliseconds.

Air Bag Volume: The volume of the driver air bag has remained about the same over the years, at anaverage of about 56 liters. On the passenger side, the volume has decreased from an average of about

11

160 liters in MY 1993 to about 120 liters in MY 1998.

Number of Tethers: The number of tethers for the driver air bag has varied over the years. In theearly years either “0” or “3 or more” prevailed. In the later years there has been a trend toward “2”tethers. On the passenger side, no clear trend exists, with manufacturers using all combinations oftethers, but the use of “no tethers” has been the most common.

Driver Air Bag Deployment Distance: The maximum extent to which the driver air bag deploys hasdecreased somewhat over the years, from an average of 15 to 16 inches in the early years to about 14inches in MY 1998. The proximity to the Seating Reference Point (SRP) has changed. The current airbags do not extend as close to the SRP as previous air bags did. Lateral deployment of the driver airbag has decreased also, from an average of about 27 inches in width in MY 1990 to about 25 inches inMY 1998.

Passenger Air Bag Deployment Distance: For top-mounted air bags, the fore-aft mounting locationof the air bag relative to the front of the instrument panel has remained constant at an average of aboutseven inches. For mid-mounted air bags the average distance from the center of the door opening tothe top of the instrument panel has also remained constant at an average of about four inches. Theaverage mounting height for mid-mounted air bags relative to the SRP has decreased somewhat fromabout 15 inches in MY 1993 to about 13 inches in MY 1998. The deployment distance (maximumextent to which the air bag deploys) of top-mounted air bags, relative to the center of the air bag cover,has remained steady at an average of about 27 to 28 inches. For mid-mounted air bags, this distancehas decreased over the years from about 29 inches in MY 1993 to about 23 inches for MYs 1996-1998. For these mid-mounted air bags, proximity to the SRP (maximum extent to which the air bagdeploys relative to a transverse vertical plane that passes through the SRP) has decreased about anaverage of eight to nine inches, from overlapping the SRP by six inches in MY 1993 to not reaching theSRP by an average of two to three inches in MYs 1996 through 1998. The maximum lateral extent ofthe passenger air bags has decreased from an average of about 31 inches in MY 1993 to about 24inches in MY 1998.

Inflator Type: No trend was observed in inflator type on the driver side, with almost all manufacturersusing a pyrotechnic type. On the passenger side, hybrid types have made an appearance over the pastfive years, and are currently being used in about half of the vehicles.

Inflating Agent: Sodium azide is by far the most predominant agent in the modules on the driver side. Arcite was used in a few vehicles in MY 1998. On the passenger side, argon, PVC, hydrogen, andhelium have been used to replace sodium azide, with approximately 50 percent of the vehicles usingnon-sodium azide agents in MY 1998.

Multi-Stage Inflation: Multi-stage inflators were not used in the IR fleet on either the driver orpassenger side.

Seat Belt Stiffness: For the driver and passenger sides, the seat belt stiffness has remained about

12

I n c r e a s i n g T i m e

Incr

easi

ng

Pres

sure

P r e s s u r e D a t a C u r v e

P e a k P r e s s u r e

R i s e R a t e = ∆ p / ∆ t

∆ p

∆ t

Figure 1. Illustrative Tank Test Data.

constant at around eight to nine percent elongation per unit load.

Load Limiters: Load limiters have been introduced into the fleet in increasing numbers. On the driverside they have increased from none in MY 1990 to about 40 percent of the vehicles in MY 1998. Onthe passenger side, a similar trend was observed.

Pre-Tensioners: Pre-tensioners were used in a small percentage of the vehicles through MY 1997. InMY 1998, their use in vehicles increased to about 15 percent.

Web Clamps: Web clamp use has been varied over the years from about five to 30 percent.

Number, Location, and Type of Air Bag Controller Sensors: There has been a trend towardfewer sensors over the years. In the early years, 3, 4, or more sensors predominated. In the lateryears, the use of single point sensors has grown to over 40 percent. There has been a trend of movingsensors from the crush zone in the early years to inside the occupant compartment in the later years. The type of sensor has also changed over the years, from electromechanical in the early years (about85 percent in MY 1990) to electronic type sensors in the later MYs (about 50 percent in MY 1998).

3.2 Tank Test Data

Air bag inflator output performance characteristics often are defined using a “tank test.” In a tank test,the inflator is placed in a pressure vessel and deployed. A photo of a tank test vessel is found inAppendix C. A time history of the pressure inside the pressure vessel is measured. A typical testoutcome is depicted in Figure 1.

13

0

25

50

75

100

Wei

ghte

d A

ir B

ag V

olum

e (l)

1990 1991 1992 1993 1994 1995 1996 1997 1998Model Year

Figure 2. Weighted Average Air Bag Volume for IR Fleet by Model Year, Driver Side.

In response to the IR, the manufacturers supplied NHTSA these data for the driver and passenger airbag inflators for all models equipped with air bags. The data were presented in graphical form. Usingthese graphs, NHTSA determined the average peak pressure and rise rate for each inflator.

Determination of Peak Pressure and Rise Rate:The average rise rate was approximated by NHTSA by manually fitting a best-fit line to the data in thearea where the pressure was changing the fastest, and then determining the slope of the line. The peakpressure was defined as the maximum pressure obtained in the pressure vessel during the test. Typically this occurred at or near the end of the data curve.

Adjustment for Vehicle Air Bag Size: Both driver and passenger air bag inflators were analyzed. Thefirst step in analyzing these inflator tank tests was to normalize for the volume of the air bag installed inthe vehicle. This was done by holding the pressure-volume ratio constant, i.e., the adjusted pressure isequal to the peak pressure from the tank test times the volume of the tank divided by the volume of theair bag installed in the vehicle. A similar process was used for rise rate. Since all inflators are tested instandard-size test tanks, but may be designed for use with different size air bags, the agency believedthat this normalization was necessary to conduct a valid comparison of different air bag characteristics. In particular, passenger air bags are much larger than driver air bags. The average air bag volumes bymodel year for driver and passenger seat positions are presented in Figures 2 and 3, respectively. While there has been little change in driver air bag volume from one model year to the next, thepassenger side shows a significant reduction in air bag volume in later years, as seen in Figure 3.

14

0

50

100

150

200

250

Wei

ghte

d A

ir B

ag V

olum

e (l)

1990 1991 1992 1993 1994 1995 1996 1997 1998Model Year

Figure 3. Weighted Average Air Bag Volume for IR Fleet, by Model Year, Passenger Side.

The weighted average for the driver air bag volume in the IR fleet has remained fairly constant at about55 liters, while the passenger air bag volume has decreased by a factor of nearly 2, from an average ofover 200 liters in MY 1990 to about 120 liters in MY 1998. The rate of decrease in volume on thepassenger side has leveled off during the past 3 years. Thus, based on the individualmake/model/model year combination, the peak pressure and rise rate tank test data were adjusted. Ifthe air bag was larger in volume than the tank volume, the peak pressure and rise rate were reduced bythe ratio of these volumes and vice-versa. These data will be referred to as “adjusted data.”

3.3 Driver Air Bag Analysis

The adjusted data for the driver air bag inflators was used to determine the weighted average for the IRFleet by model year. Figures 4 and 5 present these data for the peak pressure and rise rate by modelyear.

15

100

150

200

250

300

Pea

k P

ress

ure

(kpa

)

1990 1991 1992 1993 1994 1995 1996 1997 1998Model Year

11%

Figure 4. Weighted Average Adjusted Driver Air Bag Inflator Peak Pressure by Model Year.

3

4

5

6

7

8

9

Rat

e (k

pa/m

sec)

1990 1991 1992 1993 1994 1995 1996 1997 1998Model Year

22%

Figure 5. Weighted Average Adjusted Driver Air Bag Inflator Rise Rate, by Model Year.

In Figure 4, adjusted peak pressure from the IR Fleet’s air bag inflator output is seen to increase slightlyfrom MY 1990 through MY 1997. From MY 1997 to MY 1998 the average peak pressuredecreased by about 11 percent. Likewise, as seen in Figure 5, the average adjusted rise rate data forthe driver air bag inflators show a similar trend, but there was a larger decrease in MY 1998 from theprevious years. Figure 6 presents a composite of the data, showing a cross-plot of the average peakpressure and rise rate data.

16

0

50

100

150

200

250

300

Pea

k P

ress

ure

(kpa

)

0 1 2 3 4 5 6 7 8 9 10 Rate (kpa/msec)

MY 1998

MY 1990-1997 averages

Data adjusted for air bag volume

Figure 6. Weighted Average Adjusted Driver Air Bag Inflator Data.

Figure 6 shows a distinct clustering of the MY 1990 through 1997 IR Fleet vehicles. The MY 1998data show that the IR Fleet has a lower average rise rate and average peak pressure. This trend isshown in Table 2 where the MY 1997 vehicles are compared to the MY 1998 vehicles.

Table 2. Trend Data for Weighted Average Adjusted Driver Air Bag Inflator PeakPressure and Rise Rate.

Data Type MY 1997 vehicles MY 1998 vehicles Percent change

Peak Pressure 208 kpa 186 kpa 11%

Rise Rate 8.2 kpa/msec 6.4 kpa/msec 22%

100 kpa = 14.7 psi = 1 atmosphere

Figure 7 depicts the data presented in Table 2 in graphical form. Each line represents a compositepressure time history of the vehicles in the IR fleet for the two model years. The variation in rate ofinflation (rise rate) is shown by the change in slope in the first portion of the curves.

17

0

50

100

150

200

250

Pre

ssur

e (k

pa)

0 10 20 30 40 50 60 70 80 Time (msec)

1998 Composite

1997 Composite

Rate of Inflation

Peak Pressure

Figure 7 Graphical Representation of Weighted Average Adjusted Driver Air Bag Inflator Output forIR Fleet Comparing MY 1997 to MY 1998.

Another way to look at the change in adjusted pressure and rise rate data is by segmenting the vehiclesinto three categories: 1) those which increased peak pressure or rise rate, i.e., the adjusted peakpressure or rise rate for MY 1998 was higher than that for MY 1997, 2) those which remained thesame, i.e., having the same value for peak pressure or rise rate for MY 1998 as for MY 1997, and 3)those which decreased these same parameters, i.e., the average air bag peak pressure or rise ratedropped from MY 1997 to MY 1998. This analysis is a pair analysis, hence only those vehicles whichwere manufactured both in MY 1997 and 1998 are considered. Figure 8 presents this data, whichshows that while the majority of the MY 1998 vehicles were designed with a lower air bag inflatoroutput (measured as peak pressure or rise rate) than their MY 1997 equivalent, approximately onethird of the vehicles had no change, and some vehicles increased these parameters.

18

0

10

20

30

40

50

60

Per

cent

Increased No Change Decreased

Rise Rate Peak Pressure

Figure 8. Adjusted Driver Air Bag Inflator Characteristics, by Direction of Change in Rise Rate andPeak Pressure.

Figures 9 and 10 show the frequency distribution of air bags in a 3-dimensional format with theadjusted rise rate and peak pressure being shown on the x and y axes, for MYs 1997 and 1998,respectively. The vertical height of the bars indicate the number of vehicles with each combination ofadjusted peak pressure and rise rate.

19

3-6 6-9 9-1212-15Rise Rate (kpa/msec)

300-350250-300

200-250150-200

100-150

Pressure (kpa)

Figure 9. Frequency Distribution Plot showing Concentration Areas for Rise Rate and Peak Pressure,Adjusted Driver Air Bag Inflator Output, MY 1997.


300-350250-300

200-250150-200

100-150

Pressure (kpa)

Figure 10. Frequency Distribution Plot showing Concentration Areas for Rise Rate and PeakPressure, Adjusted Driver Air Bag Inflator Output, MY 1998.

Figures 9 and 10 confirm that there has been a general shift toward lower adjusted peak pressure andrise rate in MY 1998 vehicles, compared to MY 1997 vehicles.

20

0

2

4

6

8

10

Veh

icle

s (m

illio

ns)

1990 1991 1992 1993 1994 1995 1996 1997 1998Model Year

Driver Passenger

Figure 11. Vehicles in the IR Fleet with Driver or Passenger Air Bags, by Model Year.

3.4 Introduction of Passenger Air Bags in Fleet

Figure 11 shows the number of vehicles equipped with driver and passenger air bags in the IR fleet bymodel year. Passenger air bags were not installed in large numbers when air bags were first introducedin the early 1990's.

Figure 12 presents the number of light trucks and vans (LTV) equipped with passenger air bags. Review of this figure shows the rate of change in the number of passenger air bags installed in LTVswas very high, on average increasing by about 1,000,000 trucks per year between MY 1995 and MY1998.

21

0

1

2

3

4

5

Tru

cks

(mill

ions

)

1990 1991 1992 1993 1994 1995 1996 1997 1998Model Year

Figure 12. LTVs in the IR Fleet with Passenger Air Bags, by Model Year.

These two data sets (passenger air bags in general and LTVs with passenger air bags) are presented togive the reader some context in reviewing the passenger air bag data. These analyses reflect themanufacturers’ IR submissions for each model year, hence they include all vehicles reported by themanufacturers. With the analysis presented in this report utilizing model year averages to establishtrends, there is a possibility that these two trends could confound other data trends, as follows:

1) During the first few years covered by the IR, there were relatively few vehicles equipped withpassenger air bags compared to the later years. Additionally, only two manufacturers offeredthese devices in the first year or two. To remove possible biases in the trend analysis, NHTSAonly analyzed the later portion of the IR data in the analyses in this section, MYs 1994 through1998, to obtain passenger air bag inflator characteristics.

2) Additionally, there were no LTVs in the IR fleet equipped with passenger air bags until MY1994. LTVs are generally larger than passenger cars, hence they may have different occupantprotection design characteristics, particularly on the passenger side. These characteristics couldhave as much or more of an effect on the IR Fleet trends as emerging technology has had.

3.5 Passenger Air Bag Analysis

A similar analysis as that performed on the driver air bags was conducted to quantify the passenger airbag inflator output characteristics. Figures 13 and 14 shows the average weighted adjusted data for thepassenger air bag inflator output for both the peak pressure and rise rate.

22

100

150

200

250

300

Pea

k P

ress

ure

(kpa

)

1994 1995 1996 1997 1998Model Year

10%

Figure 13. Weighted Average Adjusted Passenger Air Bag Inflator Peak Pressure, by Model Year.

3

4

5

6

7

8

9

Rat

e (k

pa/m

sec)

1994 1995 1996 1997 1998Model Year

14%

Figure 14. Weighted Average Adjusted Passenger Air Bag Inflator Rise Rate, by Model Year.

As shown in Figure 13, the average peak pressure rose steadily until MY 1997, after which it droppedsignificantly, about 10 percent. A similar trend is seen in the average adjusted rise rate data shown in

23

0

50

100

150

200

250

300

Pea

k P

ress

ure

(kpa

)

0 1 2 3 4 5 6 7 8 9 10 Rate (kpa/mesc)

Data adjusted for air bag volume

MY 1996& 1997

MY 1998

MY 1994& 1995

Figure 15. Weighted Average Adjusted Passenger Air Bag Inflator Data.

Figure 14.

The composite plot is shown in Figure 15. Here the distinct trend observed in the more mature driverair bag systems is not seen, except when comparing the MY 1996 and 1997 IR Fleet vehicles to theMY 1998 IR Fleet vehicles.

Trend data comparing the MY 1997 vehicles to the MY 1998 vehicles are shown in Table 3.

Table 3. Trend Data for Weighted Average Adjusted Passenger Air Bag Inflator PeakPressure and Rise Rate.

Data Type MY 1997 vehicles MY 1998 vehicles Percent change

Peak Pressure 268 242 10%

Rise Rate 7.1 6.1 14%

100 kpa = 14.7 psi = 1 atmosphere

Figure 16 presents a graphical representation of the rise rate and peak pressure for the passenger side.

24

0

50

100

150

200

250

300

Pre

ssur

e (k

pa)

0 10 20 30 40 50 60 70 80 Time (msec)

1998 Composite

1997 Composite

Rate of Inflation

Peak Pressure

Figure 16. Graphical Representation of Average Adjusted Passenger Air Bag Inflator Output for IRFleet Comparing MY 1997 to MY 1998.

0

10

20

30

40

50

Per

cent

Increased No Change Decreased

Rise Rate Peak Pressure

Figure 17. Adjusted Passenger-Side Air Bag Inflator Characteristics, by Direction of Change in RiseRate and Peak Pressure.

The change in pressure and pressure rise rate for the passenger air bag inflators is shown in Figure 17. The plot indicates about 10 to 15 percent of the vehicles were equipped with passenger air bags with“increased” rise rate or peak pressure, while the remainder were split roughly equally between “no-change” or “decreased” rise rate and/or peak pressure.

25


350-400300-350

250-300200-250

150-200

Pressure (kpa)

Figure 18. Frequency Distribution Plot showing Concentration Areas for Average Rise Rate andPeak Pressure, Adjusted Passenger Air Bag Inflator Output, MY 1997.

The frequency distribution plots for the passenger air bags are found in Figures 18 and 19. As with thedriver air bags, there is a distinct migration toward the lower values of peak pressure and rise rate whenMY 1997 and 1998 vehicles are compared.

3 IARVs are shown in two formats, engineering units and normalized. In the normalizedformat, the IARV is divided by the reference value for the particular criteria, hence a value of 1 wouldrepresent the maximum acceptable level.

26


350-400300-350

250-300200-250

150-200

Pressure (kpa)

Figure 19. Frequency Distribution Plot showing Concentration Areas for Average Rise Rate andPeak Pressure, Adjusted Passenger Air Bag Inflator Output, MY 1998.

4.0 Air Bag Performance in Late Model Passenger Vehicles

4.1 NHTSA’s Out-of Position Testing

To evaluate the potential adverse effects of air bag deployment, NHTSA conducted out-of-positiontests with different sized dummies using both driver and passenger air bag systems. For the evaluationof driver air bags, 5th percentile female dummies were tested in two different positions. For theevaluation of passenger air bags, 6-year-old child dummies also were tested in two different positions. (See Appendix D for reference data, discussion of the rationale, and dummy setup for the out-of-position testing.) The two positions used on each side were intended to provide air bag loadings to thechest and to the head/neck complex, the body regions in which severe and fatal injuries have beenobserved in the real world crashes. Since these tests represent the worst case scenarios involving airbag deployments, dummy measurements were expected to be relatively high.

4.1.1 Driver Air Bag TestingResults from the 5th percentile female dummy tests using MY 1996, 1998 and 1999 air bag systems arefound in Appendix D in Tables D-1 and D-2. For both Position 1 and 2 configurations, the test resultsindicate that each of the tested vehicles met the injury assessment reference value (IARV3) for the head

27

injury criterion, the chest acceleration, and the chest deflection. The IARV for the neck injury criterion(shown as Nij in the Tables in Appendix D) was exceeded in both Position 1 and 2 testing. Tables 4and 5 summarize these data. It is noted that the average neck injury measurement decreased with eachmodel year.

Table 4. Neck Injury Data for Out-of-Position Testing for Position 1, by Model Year.

Vehicle ModelYear

Vehicles Exceeding the NeckInjury Reference Value

out ofthe Number Tested

Percent Average Neck InjuryMeasurement

1996 3 of 4 75 1.66

1998 5 of 5 100 1.44

1999 2 of 6 33 0.90

Table 5. Neck Injury Data for Out-of-Position Testing for Position 2, by Model Year.

Vehicle ModelYear

Vehicles Exceeding the NeckInjury Reference Value

out ofthe Number Tested

Percent Average Neck InjuryMeasurement

1996 3 of 4 75 1.60

1998 5 of 5 100 0.83

1999 0 of 6 0 0.47

As with position 1, the average neck injury measurement decreased with each model year in position 2. Figure 20 presents these data graphically.

28

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Figure 20. Average Test Results for Neck Injury Measurements for Driver Out-of-Position Testingwith 5th Percentile Female Dummy.

4.1.2 Passenger Air Bag TestingResults from the 6-year-old child dummy tests using MY 1996, 1998 and 1999 air bag systems arefound in Appendix D in Table D-3. For the Position 1 test configuration, the results indicate that thehead injury criterion, the neck injury criterion, the chest acceleration, and the chest deflectionmeasurements exceeded the IARV in some of the tested vehicles. The average injury measurement forthe head injury criterion, neck injury criterion, the chest acceleration, and chest deflection decreasedwith the newer model year vehicles. These data are depicted in Figure 21. Position 2 data are notpresented here since Position 2 tests were only conducted for MY 1999 vehicles.

29

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rage

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MY 96 MY 98 MY 99

15 ms HIC Max Nij Chest Acc Chest Defl

Figure 21. Average Normalized Injury Criteria for Passenger Out-of-Position Testing with 6-Year-Old Child Dummy–Position 1.

4.1.3 Two-Stage Air Bag TestingThe 1999 Acura RL, which has dual-stage passenger air bag, was tested in the Positions 1 and 2 in twoways: (1) firing only the first stage and (2) firing the both stages with a 40 ms delay between the twostages. Position 2 data are presented in Table D-4.

Table 6. Neck Injury Reference Values for Acura RL Dual Stage Testing with Out-of-Position Dummy Placement.


First Stage Only 0.91 0.83

First Stage followed by Second Stage after 40 msec Delay 1.26 0.94

Thus, the first stage Acura RL was the only passenger air bag system which passed the neck injurycriteria in both test configurations.

4.1.4 Distance From the Air Bag TestingIn addition to the aforementioned out-of-position testing, additional testing was undertaken to quantifythe effect of proximity of the dummy to the passenger air bag module on neck injury. A series of testswere run using a modified Position 1 configuration. The modification entailed the placement of the 6-year-old child dummy four and eight inches away from the air bag. These tests were conducted on MY1996 and 1998 air bag systems. The results are shown in Table D-3. While most of the testedsystems exceeded the IARVs for clearances of zero and four inches, a large majority met the

30

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Figure 22. Average Normalized HIC 15 msec for Passenger Out-of-Position Testing with 6-Year-Old Child Dummy–Position 1 at Various Clearances.

requirements with eight inches clearance. Also, the average of each of the injury measures decreasedas the distance away from the module increased. These data demonstrate that with the newertechnology, occupants can be closer to the air bag without being subjected to increased risk of injury. Figures 22 through 25 present these data graphically.

31

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MY 96 MY 98

Figure 23. Average Normalized Neck Criteria for Passenger Out-of-Position Testing with 6-Year-Old Child Dummy–Position 1 at Various Clearances.

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Figure 24. Average Normalized Chest Acceleration for Passenger Out-of-Position Testing with6-Year-Old Child Dummy–Position 1 at Various Clearances.

32

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Figure 25. Average Normalized Chest Deflection for Passenger Out-of-Position Testing with 6-Year-Old Child Dummy–Position 1 at Various Clearances.

4.2 Performance of New Model Vehicles with Redesigned Air BagSystems in Rigid Barrier Tests

In 1997, the generic sled test option was introduced as a temporary alternative to the rigid barrier testto allow automakers to rapidly install less aggressive air bags. To check the performance of theseredesigned air bags high-speed crashes, NHTSA conducted a series of FMVSS No. 208 rigid barriertests in thirteen MY 1998 and 1999 production vehicles with unbelted 50th percentile male dummies inthe driver and right front passenger seating positions. Details on these tests are provided in AppendixD, including supporting data and graphical representations of the injury criteria.

The injury measures obtained from these 13 tests for each seating position were normalized andaveraged by model years. These are shown in Figures 26 and 27, driver and passenger data,respectively. Included for comparison are a set of equivalent vehicles from pre-98 model years. Thepre-98 vehicle set is comprised of the same vehicles as the vehicles tested in the MY 1998 and MY1999 program, with two exceptions. In MY 1998, there was not an equivalent model to the MY 1999Acura RL and earlier versions of the Toyota Tacoma did not have a passenger side air bag. The pre-98 data came from NHTSA’s compliance crash test program. There were no Nij data for the oldervehicles, because the dummies used in the tests of the pre-98 vehicles were not instrumented tomeasure neck injury measures.

The average injury measures in the MY 1998 and MY 1999 vehicles increased only slightly for most ofthe measures, and in some instances actually decreased. It is interesting to note that even though theMY 1998 and 1999 vehicles tested showed large improvement in out-of-position performance, these

33

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Pre-MY98 MY 98 MY 99

Figure 26. Driver Normalized Injury Measures in 30 mph Unbelted Barrier Tests.

same systems also performed very well overall in the 30 mph unbelted barrier test. Indeed, althoughthere was some variation among the vehicles, the average values were no greater than 81 percent of theIARVs.

34

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Pre-MY98 MY 98 MY 99

Figure 27. Right Front Passenger Normalized Injury Measures in 30 mph Unbelted Barrier Tests.

5.0 Discussion of Evolving Air Bag Fatality Trends Using SCI Data

As of September 1, 1999, NHTSA’s Special Crash Investigations (SCI) Program has confirmed over180 crashes involving air bag deployment-related fatalities and serious injuries. In addition, SCI isreviewing an additional 50 crashes. Included in the confirmed number are 83 fatal children injured bythe deploying air bag, of which eighteen were in rear facing child safety seats.

NHTSA used R.L. Polk vehicle registration data to determine the number of new air bag-equippedpassenger cars and light trucks registered in the United States for each model year. These registrationcounts are used to normalize the SCI fatality counts to obtain rate data, i.e., the number of air bag-related fatalities per million registered vehicle years (MRVY). This analysis includes MYs 1988through 1999. The SCI fatality counts are based on confirmed and unconfirmed data. The majority ofthe SCI cases are confirmed within the same crash year; however, some cases are not located andconfirmed for several years after the crash date. The supporting data for these figures is presented inAppendix E.

Figures 28 and 29 present the data for 12-month intervals for driver and passenger air bags. The datawas calculated by dividing the SCI count of fatal crashes for each 12-month interval by the totalnumber of registered vehicles with driver or passenger air bags during that same interval. Each 12-month interval was aligned with the vehicle production year, hence it starts in September and ends inAugust.

35

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87-88 88-89 89-90 90-91 91-92 92-93 93-94 94-95 95-96 96-97 97-98 98-9912 Month Period

Recent Trend is Down

Figure 28. SCI Data for Fatal Drivers Normalized for Registrations of Vehicles with Driver Air Bags,by 12 Month Interval.

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Recent trend is Down

Figure 29. SCI Data for Fatal Passengers Normalized for Registrations of Vehicles with PassengerAir Bags, by 12 Month Interval.

With driver air bags, there has been a decrease in the fatality rate beginning in the 1996-1997 interval,dropping from 0.25 fatalities per MRVY to 0.05 fatalities per MRVY in the current period. Passenger

36

air bags have undergone even a larger decrease, dropping from about 0.8 fatalities per MRVY in the96-97 interval to about 0.2 in the current interval.

Figures 30 and 31 present model year analyses using the SCI data. The vehicle model year data werecalculated by dividing the number of SCI fatalities for a given model year by the product of thecumulative number of vehicles registered (and equipped with a driver or passenger air bag) for thesemodel year vehicles, times the number of years that these model year vehicles have been on the road. Hence, Figures 30 and 31 provide the equivalent of model year vehicle fatality rates, while Figures 28

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1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999Model Year

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Figure 30. SCI Data for Fatal Drivers Normalized for Vehicle Registrations, by Model Year.

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Figure 31. SCI Data for Fatal Passengers Normalized for Vehicle Registrations, by Model Year.

and 29 provide calendar year fatality rates.On the driver side, there has been a decrease in the fatalityrate beginning with MY 1996, dropping from 0.15 fatalities per MRVY in MY 1996 to 0.05 fatalitiesper MRVY in MY 1998. As of September 1, 1999, there have been no driver air bag fatalities in MY1999 vehicles. On the passenger side, the trend has been downward, in recent model years, fromabout 0.4 fatalities per MRVY in MYs 1996 and 1997 to about 0.25 in MY 1999 vehicles.

38

6.0 Findings

• On average, the inflator outputs of recently redesigned air bags have been significantly reduced. While there are variations among manufacturers and among vehicles of each manufacturer,analysis of the data provided by the manufacturers show a significant reduction in the averagepeak pressure and pressure rise rate of MY 1998 air bags in comparison to earlier air bags. However, those parameters increased in approximately ten percent of the vehicles covered bythe information request and approximately one third showed no change.

• Changes in air bag volumes, vent sizes, inflator characteristics and other design changes have allcontributed to a reduction in the safety risk from air bags, which is reflected in the dummy injurymeasures obtained from static deployment of air bags of various model years as well as in realworld crash investigations.

• Based on static and dynamic tests using adult and child dummies and the injury measuresobtained in those tests, it is clear that air bags in recent MY 1998 and 1999 vehicles are lessaggressive than the pre-MY 1998 air bags. As such, these air bags generally pose less of aninjury risk to out-of-position occupants. The special crash investigations of real-world casestend to confirm this general trend showing a significant reduction in fatality rates due to air bagsin recent MY vehicles.

• In high speed rigid barrier tests at 30 mph of seven MY 1998 and six MY 1999 vehicles,unbelted, 50th percentile male dummies were used in the driver and passenger seating positions.Three of the MY 1999 vehicles were also tested at 30 mph using 5th percentile unbelteddummies in the driver and passenger positions. The dummy injury measures for the 50th

percentile male driver dummy showed that the HIC, chest ‘g’, chest deflection and the neckinjury measures (Nij) were all within the threshold values. In a MY 1999 vehicle, the femur loadexceeded the limit. For the passenger dummy, the chest ‘g’ value exceeded the limit by 1.4 ‘g’in one vehicle and all others met the requirements. In the tests conducted using the 5th percentilefemale dummy, the Nij exceeded the threshold value for the driver and the chest ‘g’, for thepassenger in one vehicle. In another vehicle, the Nij exceeded the limit, for the passengerdummy.

• Manufacturers have made many changes to air bag designs. They are also on the threshold ofmaking a significant leap in introduction of sophisticated technologies to improve air bagperformance. For example, tailored inflation to suit different size occupants located in variouspositions in relation to the air bag and to match the severity of the crash will be a reality in thenot too distant future. NHTSA’s ongoing rulemaking to require advanced air bags will ensurethat future air bags provide improved protection of belted as well as unbelted occupants ofdifferent sizes in moderate to high speed crashes, while minimizing risks posed by air bags toinfants, children, and other occupants, especially in low speed crashes.

A-1

Appendix A. Model Year Trend Analysis

This appendix presents a number of graphical presentations of the data contained in the air baginformation request database. Each page contains:

C the title of the information presented;C the specific question number and verbal description of the question from the original information

request sent to manufacturers (located at the bottom left of each page);C the particular graph;C a diagram (if appropriate) providing a definition and frame of reference for the information

presented (located on the right of the page); and C a discussion of the information presented (also located on the right of the page).

The list of charts, presented on pages A-3 to A-4, describes all of the information presented in theappendix. The page number is located on the bottom left corner of each page.

The x-axis of each graph represents the model year of the vehicles. The data presented in the graphsrepresent the actual responses from manufacturers for each make/model/model year combinationWEIGHTED by the number of vehicles of that particular make/model/model year that were registeredin the U.S. according to R.L. Polk’s National Vehicle Population Profile. This weighting is an importantfactor in developing these estimates since manufacturers provided information for each of their modelsand sub-models. For example, Mercedes-Benz, which sells relatively few vehicles each year,presented information on almost as many different models as General Motors, which has many differentname plates built on a smaller number of similar platforms. The weighting gives the proper relativeimportance of each make/model in accordance with the numbers of vehicles on the road.

As an example of the information provided, the first graph shows the information for question A1A1 –Air Bag Location, Mounting and Deployment. The title of the graph is – Driver Side Air Bag: Distribution of Module from Plane A, 1990-1998. To the right of the graph is a diagram of PlaneA and the definition – Plane A is the plane tangent to the face of the steering wheel rim. This isfollowed by a brief discussion of the data.

Each of the graphs present one of two types of information – categorical and numerical. For example,the first graph presents the air bag location information, which is categorical – either Recessed, Flush orProtruded relative to the steering wheel, as shown in the diagram to the right of the graph. Thecategorical information is presented as stacked bar charts, adding up to 100 percent.

The second graph presents numerical information – Driver Side Air Bag: Distance from Plane A tothe Portion of the Air Bag Module Closest to the Driver, 1990-1998. The numerical information ispresented as a vertical line marking the 5th percentile, 95th percentile and average values. Eachvertical line extends between the 5th percentile (that is, 5 percent of the vehicles registered in that model

A-2

year have values less than or equal to the 5th percentile value) and the 95th percentile (that is, 95percent of the vehicles registered in that model year have values less than or equal to the 95th percentilevalue, and conversely, 5 percent of the vehicles registered have values greater than or equal to the 95th

percentile value) observed for the various vehicles for that model year in the database. The 5th and 95th

percentiles were used in place of upper and lower standard deviations because many of the attributesdo not follow a symmetrical (e.g., bell shaped) distribution, and the percentiles are less prone todistortions that can result from a few large outliers. The average value is marked on the vertical line bya solid box.

In a few cases, all of the data points provided were the same (e.g., Number of Chambers in the AirBag) so no graph is provided. A simple description, such as: “For all model years, there was onlyone chamber for both the driver and passenger air bags” is provided.

Appendix A: List of ChartsCharts Page

A1A1 Driver Side Air Bag: Distribution of Module from Plane A, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5

A1A2 Driver Side Air Bag: Distance from Plane A to the Portion of the Air Bag Module Closest to the Driver, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-6

A1A3 Driver Side Air Bag Modules Designed to Move Away from the Occupant at the Time of Deployment, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-7

A1A4 Passenger Side Air Bag Modules Designed to Move Away from the Occupant at the Time of Deployment, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-8

A1B1 Passenger Side Air Bag: Distribution of Mounting Location, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-9

B1-d Driver Side Air Bag: Area of the Opening, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-10B1-p Passenger Side Air Bag: Area of the Opening, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-10

B1-d Driver Side Air Bag: Area of the Cover, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-11B1-p Passenger Side Air Bag: Area of the Cover, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-11

B2-d Driver Side Air Bag: Minimum Breakout Pressure, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-12B2-p Passenger Side Air Bag: Minimum Breakout Pressure, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-12

B3-d Driver Side Air Bag: Mass of Cover, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-13B3-p Passenger Side Air Bag: Mass of Cover, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-13

B4 Driver Side Air Bag: Tear Patterns, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-14

B4 Passenger Side Air Bag: Tear Patterns, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-15

C1A Number of Chambers in the Air Bag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-16

C1B Driver Side Air Bag: Fold Patterns, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-17

C1B Passenger Side Air Bag: Fold Patterns, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-18

C1C Material of Air Bag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-19

C1C-d Driver Side Air Bag: Mass of Air Bag, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-20C1C-p Passenger Side Air Bag: Mass of Air Bag, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-20

C1D-d Driver Side Air Bag: Inflation Time, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-21C1D-p Passenger Side Air Bag: Inflation Time, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-21

C1E-d Driver Side Air Bag: Volume of Fully Inflated Air Bag, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-22C1E-p Passenger Side Air Bag: Volume of Fully Inflated Air Bag, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-22

C1F-d Driver Side Air Bag: Number of Tethers, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-23C1F-p Passenger Side Air Bag: Number of Tethers, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-23

C1G1 Driver Side Air Bag: Distance between Plane J and Plane K, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-24

C1G2 Driver Side Air Bag: Distance between Plane F and Plane K, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-25

C1G3 Driver Side Air Bag: Maximum Distance the Air Bag Reaches Laterally on Each Side of Plane N, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-26

C1G4 Passenger Side Air Bag: Distance from Plane C to Plane E for Top-Mounted Air Bags, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A -27

A-3

Appendix A: List of Charts Charts Page

C1G5 Passenger Side Air Bag: Distance between Plane B and Plane I forAir Bags Other than Top-Mounted, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-28

C1G6 Passenger Side Air Bag: Distance between Planes H and I for Air Bags Other than Top-Mounted, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-29

C1H1 Passenger Side Air Bag: Distance between Plane C and Plane L for Top-Mounted Air Bags, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-30

C1H2 Passenger Side Air Bag: Distance between Plane D and Plane L for Air Bags Other Than Top-Mounted, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-31

C1H3 Passenger Side Air Bag: Distance between Planes G and L for Air Bags Other than Top-Mounted, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-32

C1H4 Passenger Side Air Bag: Maximum Distance the Air Bag Reaches Laterally on Each Side of Plane M, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-33

C2A-IT-d Driver Side Air Bag: Inflator Type, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-34C2A-IT-p Passenger Side Air Bag: Inflator Type, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-34

C2A-IA-d Driver Side Air Bag: Inflating Agent, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-35C2A-IA-p Passenger Side Air Bag: Inflating Agent, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-35

C2B-d Driver Side Air Bag: Number of Inflation Stages, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-36C2B-p Passenger Side Air Bag: Number of Inflation Stages, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-36

C2C4-d Driver Side Air Bag: Scaled Rise Rate, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-37C2C4-p Passenger Side Air Bag: Scaled Rise Rate, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-37

C2C4-d Driver Side Air Bag: Scaled Peak Pressure, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-38C2C4-p Passenger Side Air Bag: Scaled Peak Pressure, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-38

D1-d Driver Side Air Bag: Stiffness of the Seat Belts (force/elongation), 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-39

D1-p Passenger Side Air Bag: Stiffness of the Seat Belts (force/elongation), 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-39

D2-d Driver Side Air Bag: Presence of Load Limiters in the Seat Belt, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-40

D2-p Passenger Side Air Bag: Presence of Load Limiters in the Seat Belt, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-40

D3-d Driver Side Air Bag: Presence of Pretensioners in the Seat Belt,1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-41

D3-p Passenger Side Air Bag: Presence of Pretensioners in the Seat Belt, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-41

D4-d Driver Side Air Bag: Presence of Web Clamps in the Seat Belt, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-42D4-p Passenger Side Air Bag: Presence of Web Clamps in the Seat Belt, 1993-1998 . . . . . . . . . . . . . . . . . . . . . . . . . A-42

E1 Number of Sensors, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-43

E1 Location of Sensors, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-44

E1 Type of Sensors, 1990-1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-45

A-4

0

10

20

30

40

50

60

70

80

90

100

PE

RC

EN

T

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR

Recessed Flush Protruded

Driver Side Air Bag: Distribution of Module from Plane A, 1990-1998

Diagram of Plane A

Definition: Plane A is the plane tangentto the face of the steering wheel rim.

Discussion: The chart depicts the variationof the placement of the air bag modulefrom Plane A. For the past seven years, thepercentage of flush air bag modules hasremained constant while the percentage ofrecessed modules has increased and thepercentage of protruded modules hasdecreased.

A1A1 (Air Bag Location, Mounting and Deployment Air Bag Characteristics in Light Motor Vehicles A-5

-40

-30

-20

-10

0

10

20

DIS

TA

NC

E F

RO

M P

LAN

E A

(M

M)

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR

95TH PERCENTILE 5TH PERCENTILE AVERAGE

Driver Side Air Bag: Distance from Plane A to the Portion of the Air Bag Module Closest to the Driver, 1990-1998

Diagram of Plane A

Discussion: Negative values depict airbags recessed with respect to the steeringwheel while positive values representprotruding air bags. The chart shows atrend towards recessed driver air bags orair bags being placed further away fromthe driver. The average distancedecreased from +2.8 mm in 1991 toapproximately -4.7 mm in 1998.


0

20

40

60

80

100

PE

RC

EN

T

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR

No Yes

Driver Side Air Bag Modules Designed to Move Away from the Occupantat the Time of Deployment, 1990-1998

Discussion: The majority of driver sideair bag modules were not designed tomove away from the driver at the time ofdeployment. In 1996, air bag modulesthat were designed to move away fromthe driver at the time of deploymentsurfaced.


0

20

40

60

80

100

PE

RC

EN

T

1993 1994 1995 1996 1997 1998MODEL YEAR

No Yes

Passenger Side Air Bag Modules Designed to Move Away from the Occupant at the Time of Deployment, 1993-1998

Discussion: The majority of passengerside air bag modules were not designed tomove away from the passenger at thetime of deployment. In 1995, air bagmodules that were designed to moveaway from the occupant at the time ofdeployment surfaced. From 1995 to1998, the number of air bags modulesthat were designed to move away fromthe occupant almost doubled.


A1B1 (Air Bag Location, Mounting and Deployment) Air Bag Characteristics in Light Motor Vehicles A-9

0

10

20

30

40

50

60

70

80

90

100

PE

RC

EN

T

1993 1994 1995 1996 1997 1998MODEL YEAR

Middle 3/4 Top

Passenger Side Air Bag: Distribution of Mounting Location, 1993-1998 Mounting of Passenger Air Bag onthe Instrument Panel

Discussion: The figure depicts thevariation of the placement of thepassenger air bag on the instrumentpanel. From 1993 to 1998, thepercentage of mid-mounted air bagsincreased while the percentage of top-mounted air bags decreased.

10000

15000

20000

25000

30000

35000 A

RE

A O

F T

HE

OP

EN

ING

(M

M^2

)

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR


Driver Side Air Bag: Area of the Opening, 1990-1998

0

20000

40000

60000

80000

100000

120000

AR

EA

OF

THE

OP

EN

ING

(M

M^2

)

1993 1994 1995 1996 1997 1998MODEL YEAR


Passenger Side Air Bag: Area of the Opening, 1993-1998

DiscussionThe charts illustrate the distribution of thearea of the opening through which the airbag is deployed.

Driver Side: The chart shows a downwardtrend towards smaller air bag openings.The average area of the opening decreasedfrom a high of approximately 26,000 mm2

in 1990 to 21,000 mm2 in 1998.

Passenger Side: As depicted in the chart,there has been a consistent trend in theaverage area of the opening ofapproximately 46,000 mm2.

B1 (Air Bag Cover Configuration and Opening during Deployment) Air Bag Characteristics in Light Motor Vehicles A-10

10000

15000

20000

25000

30000

35000

40000

45000

AR

EA

OF

THE

CO

VE

R (

MM

^2)

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR


Driver Side Air Bag: Area of the Cover, 1990-1998

0

20000

40000

60000

80000

100000

120000

AR

EA

OF

THE

CO

VE

R (

MM

^2)

1993 1994 1995 1996 1997 1998MODEL YEAR


Passenger Side Air Bag: Area of the Cover, 1993-1998

Discussion

The charts illustrate the distribution of thearea of the opening through which the airbag is deployed.

Driver Side: The chart shows a downwardtrend towards smaller air bag openings.The average area of the opening decreasedfrom a high of approximately 26,000 mm2

in 1990 to 21,000 mm2 in 1998.

Passenger Side: As depicted in the chart,there has been a consistent trend in theaverage area of the opening ofapproximately 46,000 mm2.


0

100

200

300

400

500

MIN

IMU

M B

RE

AK

OU

T P

RE

SS

UR

E (

kPa)

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR


Driver Side Air Bag: Minimum Breakout Pressure, 1990-1998

0

200

400

600

800

1000

MIN

IMU

M B

RE

AK

OU

T P

RE

SS

UR

E (

kPa)

1993 1994 1995 1996 1997 1998MODEL YEAR


Passenger Side Air Bag: Minimum Breakout Pressure, 1993-1998

Definition: The minimum breakoutpressure is the pressure required for theair bag to breakthrough the air bagmodule cover at the time of deployment. The wide range of pressures are due tothe use of different air bag cover materialor the thickness of the tear line.

Discussion: The minimum breakoutpressure was not reported forapproximately 50 percent of the driver andpassenger side air bags.

Driver Side: The average minimumbreakout pressure decreased slightly from1990 to 1992. Although there was a slightincrease in the average breakout pressurein 1993, the average pressure has beensteadily decreasing since 1994.

Passenger Side: The average minimumbreakout pressure decreased 21 percentfrom 1993 (367 kpa) to 1998 (291 kpa).


0

100

200

300

400

500

600

MA

SS

OF

TH

E C

OV

ER

(G

RA

MS

)

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR


Driver Side Air Bag: Mass of Cover, 1990-1998

0

200

400

600

800

1000

1200

1400

MA

SS

OF

THE

CO

VE

R (

GR

AM

S)

1993 1994 1995 1996 1997 1998MODEL YEAR


Passenger Side Air Bag: Mass of Cover, 1993-1998

Driver Side: From 1990 to 1994, therewas a downward trend towards a slightlylighter air bag cover. Beginning in 1995,the average mass of the cover began toincrease slightly. The average mass ofthe cover has remained basically the samefrom 1995 to 1998.

Passenger Side: The average mass of thepassenger air bag cover has fluctuatedover time. In a limited number ofmodels, the entire top of the instrumentpanel is allowed to open to permit thedeployment of the passenger air bag. Thespread between the average values andthe 95th percentile values are due to a fewdesigns in which the entire top of theinstrument panel is opened to permit airbag deployment.


0

20

40

60

80

100

PE

RC

EN

T

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR

HORIZONTAL H-SHAPED U-SHAPED I-SHAPED

Driver Side Air Bag: Tear Patterns, 1990-1998 Illustrations of Driver Side Air BagTear Patterns

Discussion: The chart depicts fourpredominant tear patterns in driver airbag covers. In 1994, the H-shaped tearpattern began decreasing in air bags whilethe I-shaped tear pattern beganincreasing. In 1995, the U-shaped tearpattern was present in approximately onepercent of all tear patterns. Thehorizontal tear pattern has comprisedbetween 20 and 28 percent of all types oftear patterns since 1990.


0

20

40

60

80

100

PE

RC

EN

T

1993 1994 1995 1996 1997 1998MODEL YEAR

HORIZONTAL H-SHAPED U-SHAPED DOOR

Passenger Side Air Bag: Tear Patterns, 1993-1998Illustrations of Passenger Side Air

Bag Tear Patterns

Discussion: The chart depicts fourpredominant tear patterns in passenger airbag covers. In 1995, the H-shaped tearpattern began increasing in air bags whilethe U-shaped tear pattern begandecreasing. The horizontal and door tearpatterns have fluctuated over the pastseveral years.


Number of Chambers in the Air Bag

For all model years, there was only one chamber in both the driver side and the passenger sige airbags.

C1A (AIR BAG INFORMATION) Air Bag Characteristics in Light Motor Vehicles A-16

0

20

40

60

80

100

PE

RC

EN

T

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR

ACCORDION MODIFIED ACCORDION

OVERLAP REVERSE ROLL

Driver Side Air Bag: Fold Patterns, 1990-1998 Illustrations of Driver Side Air BagFold Patterns

Discussion: The chart depicts fourpredominant fold patterns used for driverair bags. The reverse roll has been thepredominant fold in driver air bags since1990. In 1994, the percentage of overlapfolds began to increase while thepercentage of modified accordion foldsbegan to decrease. The presence ofaccordion folds in air bags has fluctuatedsince 1990.

C1B (AIR BAG INFORMATION) Air Bag Characteristics in Light Motor Vehicles A-17

0

20

40

60

80

100

PE

RC

EN

T

1993 1994 1995 1996 1997 1998MODEL YEAR

ACCORDION ROLL

OVERLAP ROTATED ACCORD

Passenger Side Air Bag: Fold Patterns, 1993-1998 Illustrations of Passenger Side AirBag Fold Patterns

Discussion: The chart depicts fourpredominant fold patterns used forpassenger air bags. From 1993 to 1994,accordion folds decreased approximately17 percent while the percentage of rollfolds almost doubled. Since 1993, thepercentage of overlap folds in passengerair bags has fluctuated. Rotatedaccordion folds have been increasingsince 1997.

C1B (AIR BAG INFORMATION) Air Bag Characteristics in Light Motor Vehicles A-18

Material of the Air Bag

For all model years, the manufacturers reported approximately 60 different air bag material types.Thirty-one percent of the driver air bags were Nylon and thirty-one percent of the passenger air bagswere Nylon. Most of the other material types contained some variation of Nylon or other type ofmaterial.

C1C (AIR BAG INFORMATION) Air Bag Characteristics in Light Motor Vehicles A-19

150

200

250

300

350

400

450

MA

SS

OF

AIR

BA

G (

GR

AM

S)

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR


Driver Side Air Bag: Mass of Air Bag, 1990-1998

300

400

500

600

700

800

900

MA

SS

OF

AIR

BA

G (G

RA

MS

)

1993 1994 1995 1996 1997 1998MODEL YEAR


Passenger Side Air Bag: Mass of Air Bag, 1993-1998

Driver Side: The chart shows a smalltrend towards a lighter air bag. Theaverage mass of the air bag decreasedapproximately 15 percent from 1990 (297grams) to 1998 (253 grams).

Passenger Side: The average mass of thepassenger air bag decreasedapproximately 9 percent from 1993 (630grams) to 1998 (572 grams).

C1C (AIR BAG INFORMATION) Air Bag Characteristics in Light Motor Vehicles A-20

25

30

35

40

45

50

INF

LAT

ION

TIM

E (

MIL

LIS

EC

ON

DS

)

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR


Driver Side Air Bag: Inflation Time, 1990-1998

20

30

40

50

60

70

80

90

INF

LAT

ION

TIM

E (

MIL

LIS

EC

ON

DS

)

1993 1994 1995 1996 1997 1998MODEL YEAR


Passenger Side Air Bag: Inflation Time, 1993-1998

Definition: The inflation time is the timefrom the initiation of inflation to fullinflation.

Driver Side: The chart represents aconsistent average inflation time ofapproximately 33 milliseconds for alldriver air bag modules.

Passenger Side: From 1993 to 1994, theaverage inflation time decreasedapproximately 14 percent and continuedto decrease until 1996. The averageinflation time increased slightly from1996 to 1997.

C1D (AIR BAG INFORMATION) Air Bag Characteristics in Light Motor Vehicles A-21

C1E (AIR BAG INFORMATION) Air Bag Characteristics in Light Motor Vehicles A-22

40

45

50

55

60

65

70

VO

LUM

E (

LIT

ER

S)

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR


Driver Side Air Bag: Volume of Fully Inflated Air Bag, 1990-1998

80

100

120

140

160

180

200

220

VO

LUM

E (L

ITE

RS

)

1993 1994 1995 1996 1997 1998MODEL YEAR


Passenger Side Air Bag: Volume of Fully Inflated Air Bag, 1993-1998

Driver Side: The chart shows arelatively stable average volume of thefully inflated driver air bag betweenapproximately 54 and 57 liters.

Passenger Side: As depicted in thechart, there is a downward trend in thevolume of the fully inflated passengerair bags. From 1993 to 1998, therewas a 26 percent decrease in theaverage volume of the fully inflatedair bag.

0

10

20

30

40

50

60

70

80

90

100

PE

RC

EN

T

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR

0 2 3 or more

Driver Side Air Bag: Number of Tethers, 1990-1998

0

10

20

30

40

50

60

70

80

90

100

PE

RC

EN

T

1993 1994 1995 1996 1997 1998MODEL YEAR

0 1 2 4

Passenger Side Air Bag: Number of Tethers, 1993-1998

Driver Side: The chart shows an increasingtrend towards two-tethered driver air bags.From 1990 to 1993, a majority of the driverair bags were tethered by 3 or more tethersor were untethered. From 1994 to 1998,the percentage of two-tethered air bagstripled while the percentage of untetheredair bags or air bags tethered by 3 or moretethers decreased. There were no one-tethered driver air bags.

Passenger Side: Untethered passenger airbags continue to comprise a largepercentage of all air bags. Although thepercentage of two-tethered air bagsincreased from 1993 to 1994, two-tetheredair bags have been decreasing since 1995.There were no three-tethered passenger airbags.

C1F (AIR BAG INFORMATION) Air Bag Characteristics in Light Motor Vehicles A-23

10

12

14

16

18

20

DIS

TA

NC

E B

ET

WE

EN

PLA

NE

S J

AN

D K

(IN

)

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR


Driver Side Air Bag: Distance between Plane J and Plane K, 1990-1998

Diagram of Planes

Definition: Plane J is the transversevertical plane that passes through thecenter point on the surface of the driverair bag cover. Plane K is the transversevertical plane that passes through themaximum rearward point that the driverair bag reaches at any time duringdeployment.

Discussion: The average distance betweenPlanes J and K has fluctuated slightly formany years, however, the average distancehas been relatively stable since 1995.

C1G1 (DRIVER AIR BAG DEPLOYMENT DISTANCE) Air Bag Characteristics in Light Motor Vehicles A-24

-6

-4

-2

0

2

4

6

DIS

TA

NC

E B

ET

WE

EN

PLA

NE

S F

AN

D K

(IN

)

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR


Driver Side Air Bag: Distance between Plane F and Plane K, 1990-1998

NOTE : Negative values denote deployment behind the seating reference point.

Diagram of Planes

Definition: Plane F is the transversevertical plane that passes through theseating reference point (SRP) for thedriver position. Plane K is the transversevertical plane that passes through themaximum rearward point that the driverair bag reaches at any time duringdeployment.

Discussion: The average distance betweenPlanes F and K has changed fromapproximately -2.0 inches in the earlyyears to approximately +1.0 inch in lateryears. This change indicates that themaximum rearward point is movingforward relative to the SRP.


6

8

10

12

14

16

18

MA

X D

IST

RE

AC

HE

D L

AT

ER

ALL

Y O

F P

LAN

E N

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR


Driver Side Air Bag: Maximum Distance the Air Bag Reaches Laterally on Each Side of Plane N, 1990-1998

Definition: Plane N is the longitudinalvertical plane that passes through thecenterline of the Hybrid III dummy aspositioned at the front outboard driverseating position.

Discussion: The chart depicts the trend ofthe average lateral half-width the driverair bag reaches. The half-width hasdecreased from a high of 13.8 inches in1990 to 12.3 inches in 1998, an 11percent decrease.


2

4

6

8

10

12

DIS

TA

NC

E (

INC

HE

S)

1993 1994 1995 1996 1997 1998MODEL YEAR


Passenger Side Air Bag: Distance from Plane C to Plane E for Top-Mounted AirBags

Diagram of Plane C to Plane E for Top-Mounted Air Bags

Definition: Plane C is the transversevertical plane that passes through thecenter point of the passenger air bagcover. Plane E is the transverse verticalplane tangent to the rearmost portion ofthe passenger portion of the instrumentpanel.

Discussion: The average distance fromPlane C to Plane E has remained relativelystable from 1993 to 1998.

C1G4 (Air Bag Location, Mounting and Deployment) Air Bag Characteristics in Light Motor Vehicles A-27

1

2

3

4

5

6

7

DIS

TA

NC

E B

ET

WE

EN

PLA

NE

S B

AN

D I

(IN

)

1993 1994 1995 1996 1997 1998MODEL YEAR


Passenger Side Air Bag: Distance between Plane B and Plane I for Air Bags Other than Top-Mounted, 1993-1998

Diagram of Planes B and I for AirBags Other than Top-Mounted

Definitions : Plane B is the horizontalplane tangent to the uppermost surface ofthe passenger portion of the instrumentpanel. Plane I is the horizontal plane thatpasses through the center point of thepassenger air bag module.

Discussion: As depicted in the chart, theaverage distance between Planes B and Ihas fluctuated over the years. The averagedistance has ranged from 3.4 inches to 4.0inches.


4

6

8

10

12

14

16

18

DIS

TA

NC

E B

ET

WE

EN

PLA

NE

S H

AN

D I

(IN

)

1993 1994 1995 1996 1997 1998MODEL YEAR


Passenger Side Air Bag: Distance between Planes H and I for Air Bags Other than Top-Mounted, 1993-1998

Diagram of Planes H and I for AirBags Other Than Top-Mounted

Definition: Plane H is the horizontal planethat passes through the seating referencepoint (SRP) for the front outboardpassenger seating position. Plane I is thehorizontal plane that passes through thecenter point of the passenger air bagmodule.

Discussion: The average distancebetween Planes H and I has ranged from15 inches in 1993 to 13 inches in 1998placing the air bag module slightly loweron the instrument panel.


20

22

24

26

28

30

32

34

36

DIS

TA

NC

E B

ET

WE

EN

PLA

NE

S C

AN

D L

(IN

)

1993 1994 1995 1996 1997 1998MODEL YEAR


Passenger Side Air Bag: Distance between Plane C and Plane L for Top-MountedAir Bags, 1993-1998

Diagram of Planes

Definition: Plane C is the transversevertical plane that passes through the centerpoint of the passenger air bag cover. PlaneL is the transverse vertical plane that passesthrough the maximum rearward point thatthe passenger air bag reaches at any timeduring deployment.

Discussion: The average rearwarddeployment distance of the top-mountedpassenger air bag has been relativelyconsistent since 1993.

C1H1 (PASSENGER AIR BAG DEPLOYMENT DISTANCE) Air Bag Characteristics in Light Motor Vehicles A-30

15

20

25

30

35

40

DIS

TA

NC

E B

ET

WE

EN

PLA

NE

S D

AN

D L

(IN

)

1993 1994 1995 1996 1997 1998MODEL YEAR


Passenger Side Air Bag: Distance between Plane D and Plane L for Air Bags Other Than Top-Mounted, 1993-1998

Diagram of Planes

Definition: Plane D is the vertical planetangent to the portion of the passenger airbag module closest to a normally seatedfront outboard passenger. Plane L is thetransverse vertical plane that passesthrough the maximum rearward point thatthe passenger air bag reaches at any timeduring deployment.

Discussion: From 1993 to 1996, there wasa substantial decrease (21 percent) in theaverage distance between Planes D and L.The average distance has remainedbasically the same since 1996.


-15

-10

-5

0

5

10

DIS

TA

NC

E B

ET

WE

EN

PLA

NE

S G

AN

D L

(IN

)

1993 1994 1995 1996 1997 1998MODEL YEAR


Passenger Side Air Bag: Distance between Plane G and Plane L for Air Bags Other than Top-Mounted, 1993-1998

Diagram of Planes

Definition: Plane G is the transversevertical plane that passes through the SRPfor the front outboard passenger seatingposition. Plane L is the transverse verticalplane that passes through the maximumrearward point that the passenger air bagreaches at any time during deployment.

Discussion: The chart shows a dramaticincrease in the average distance betweenPlanes G and L from 1993 to 1998. Datawere not reported for one-fourth of thevehicles.


6

8

10

12

14

16

18

20

22

MA

X D

IST

RE

AC

HE

D L

AT

ER

ALL

Y O

F P

LAN

E M

1993 1994 1995 1996 1997 1998MODEL YEAR


Passenger Side Air Bag: Maximum Distance the Air Bag Reaches Laterally on Each Side of Plane M, 1993-1998 Definition: Plane M is the longitudinal

vertical plane that passes through thecenterline of the Hybrid III dummy aspositioned at the passenger position.

Discussion: The chart shows a substantialdecrease in the distance to which the airbag reaches laterally on either side of PlaneM. Data were not reported forapproximately 34 percent of the vehicles.


0

20

40

60

80

100

PE

RC

EN

T

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR

Hybrid Pyrotechnic

Driver Side Air Bag: Inflator Type, 1990-1998

0

20

40

60

80

100

PE

RC

EN

T

1993 1994 1995 1996 1997 1998MODEL YEAR

Compressed Gas Hybrid Pyrotechnic

Passenger Side Air Bag: Inflator Type, 1993-1998

Definition: Air bag inflators can be broadlyclassified as Pyrotechnic, Compressed Gas,or Hybrid. Hybrid inflators are acombination of Pyrotechnic andCompressed Gas mechanisms.

Driver Side: One hundred percent of driverside inflators were pyrotechnic devicesprior to 1997. Hybrid inflators started toappear in the fleet in 1997 (0.1 percent)and 1998 (4 percent).

Passenger Side: In 1993, 100 percent ofthe inflators in the fleet were Pyrotechnic.Hybrid inflators started to appear in 1994(approximately 15 percent). From 1994 to1998, there was a 31 percent increase inHybrid inflators. Compressed gas inflatorscomprised a minor proportion of theinflators in 1997 and 1998.

C2A-IT (INFLATOR INFORMATION) Air Bag Characteristics in Light Motor Vehicles A-34

0

20

40

60

80

100 P

ER

CE

NT

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR

Sodium Azide Nitrogen Other

Driver Side Air Bag: Inflating Agent, 1990-1998

0

20

40

60

80

100

PE

RC

EN

T

1993 1994 1995 1996 1997 1998MODEL YEAR

Sodium Azide Argon PVC Other

Passenger Side Air Bag: Inflating Agent, 1993-1998

Definition: The inflating agent is the gasthat is generated during the inflationprocess to fill the air bag.

Driver Side: The gas generate in the driverside air bag is predominantly sodium azide.A small percentage of inflators use nitrogenas the inflating agent. In 1998, severalother inflating agents such as arcite beganto surface.

Passenger Side: Sodium azide has been thepredominant gas generant in the inflators ofpassenger air bags for many years. Poly-vinyl chloride (PVC), argon, and otheragents such as Hydrogen and Helium areshowing increased presence as the gasgenerant in the inflators.

C2A-IA (INFLATOR INFORMATION) Air Bag Characteristics in Light Motor Vehicles A-35

Driver and Passenger Side Air Bag: Number of Inflation Stages, 1990-1998

Definition: Inflation Stages can be single or multiple. Multiple Stage inflators maintain a reducedinflator output at the beginning of the inflation process and reach peak output at a later stage ofdeployment.

All of the Driver Side Air Bags from 1990 to 1998 and the Passenger Side Air Bags from1993 to 1998 in the fleet had a single stage inflation process; therefore no chart is displayedto represent the number of air bag inflation stages.

C2B (INFLATOR INFORMATION) Air Bag Characteristics in Light Motor Vehicles A-36

2

4

6

8

10

12

RIS

E R

AT

E S

CA

LED

(kp

a/m

s)

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR


Driver Side Air Bag: Scaled Rise Rate, 1990-1998

4

6

8

10

12

14

RIS

E R

AT

E S

CA

LED

(kpa

/ms)

1993 1994 1995 1996 1997 1998MODEL YEAR


Passenger Side Air Bag: Scaled Rise Rate, 1993-1998

Definition: The scaled rise rate is the rate atwhich the air bag inflation pressureincreases over time during tank tests.

Driver inflator tank test data were scaled toa 60 liter tank volume and the passengertank test data were scaled to 100 litersusing a constant PV product method.

Driver Side: Although the average scaledrise rate has fluctuated over the past severalyears, the average scaled rise ratedecreased approximately 23 percent from1997 (7.4 kpa/ms) to 1998 (5.7 kpa/ms).

Passenger Side: The average scaled riserate in the passenger air bag has alsofluctuated over the past several years. Theaverage rise rate decreased approximately14 percent from 1997 (8.6 kpa/ms) to 1998(7.4 kpa/ms).

C2C4 (INFLATOR INFORMATION) Air Bag Characteristics in Light Motor Vehicles A-37

120

140

160

180

200

220

240

260

280

PE

AK

PR

ES

SU

RE

SC

ALE

D (

kpa)

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR


Driver Side Air Bag: Scaled Peak Pressure, 1990-1998

200

250

300

350

400

450

PE

AK

PR

ES

SU

RE

SC

ALE

D (k

pa)

1993 1994 1995 1996 1997 1998MODEL YEAR


Passenger Side Air Bag: Scaled Peak Pressure, 1993-1998

Definition: The scaled peak pressure isthe maximum pressure attained during theair bag inflator tank tests.

Driver inflator tank test data were scaled toa 60 liter tank volume and the passengertank test data were scaled to 100 litersusing a constant PV product method.

Driver Side: The average scaled peakpressure decreased approximately 12percent from 1997 (189 kpa) to 1998 (167kpa).

Passenger Side: The average scaled peakpressure decreased approximately 11percent from 1997 (328 kpa) to 1998 (292kpa).

C2C4 (INFLATOR INFORMATION) Air Bag Characteristics in Light Motor Vehicles A-38

D1 (SEAT BELT TECHNOLOGY) Air Bag Characteristics in Light Motor Vehicles A-39

4

6

8

10

12

14

16

STI

FFN

ES

S (

% E

long

atio

n)

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR


Driver Side Air Bag: Stiffness of the Seat Belts (force/elongation), 1990-1998

4

6

8

10

12

14

16

ST

IFF

NE

SS

(%

Elo

ngat

ion)

1993 1994 1995 1996 1997 1998MODEL YEAR


Passenger Side Air Bag: Stiffness of the Seat Belts (force/elongation), 1993-1998

Definition: The stiffness of a seatbelt is the amount (in percent) a seatbelt stretches when subjected to aspecific force. A low percent inelongation indicates a stiffer belt.

Driver Side: The average stiffness ofthe driver seat belt showed a steadydecreasing trend from 1992 to 1997.In 1998, the driver seat belt becamestiffer.

Passenger Side: The average stiffnessof the passenger seat belt showed adecreasing trend from 1993 to 1994.From 1994 to 1997, the stiffnessremained relatively constant. Thepassenger seat belt became stiffer in1998.

0

10

20

30

40

50

60

70

80

90

100

PE

RC

EN

T

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR

No Yes

Driver Side Air Bag: Presence of Load Limiters in the Seat Belt

0

10

20

30

40

50

60

70

80

90

100

PE

RC

EN

T

1993 1994 1995 1996 1997 1998MODEL YEAR

No Yes

Passenger Side Air Bag: Presence of Load Limiters in the Seat Belt

Definition: Load limiters are devices thatlimit the forces imparted to the occupantby the seat belt during the crash event. The forces are prevented from exceedinga pre-determined level by allowing theseat belt webbing to yield when forcesreach this level.

Driver Side: In 1990, load limiters werepresent in just one percent of the fleet. In1998, limiters were present inapproximately 40 percent of the fleet.

Passenger Side: In 1994, load limiterswere present in 14 percent of the fleet,however, by 1998, the percent of limiterspresent in seat belts had tripled toapproximately 42 percent


0

10

20

30

40

50

60

70

80

90

100 P

ER

CE

NT

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR

No Yes

Driver Side Air Bag: Presence of Pretensioners in the Seat Belt

0

10

20

30

40

50

60

70

80

90

100

PE

RC

EN

T

1993 1994 1995 1996 1997 1998MODEL YEAR

No Yes

Passenger Side Air Bag: Presence of Pretensioners in the Seat Belt

Definition: Pretensioners are devices,usually pyrotechnic, to remove slack fromthe seat belt upon air bag inflation.

Driver Side: Until 1997, pretensioners werepresent in a minor proportion of thevehicles. The proportion of seat belts withpretensioners increased from 4 percent in1997 to 14 percent in 1998.

Passenger Side: The proportion ofpassenger seat belts with pretensionersshowed a decreasing trend from 1993 to1997. From 1997 to 1998, the proportionof seat belts with pretensioners increasedfrom 4 percent to 14 percent.


0

10

20

30

40

50

60

70

80

90

100 P

ER

CE

NT

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR

No Yes

Driver Side Air Bag: Presence of Web Clamps in the Seat Belt, 1990-1998

0

10

20

30

40

50

60

70

80

90

100

PE

RC

EN

T

1993 1994 1995 1996 1997 1998MODEL YEAR

No Yes

Passenger Side Air Bag: Presence of Web Clamps in the Seat Belt, 1993-1998

Definition: Web clamps are devices in theseat belt retractor that lock the webbing toprevent or minimize shoulder belt spool-out.

Driver Side: The proportion of seat beltswith web clamps increased considerablyfrom 1991 to 1992. Although thepresence of web clamps in seat beltsfluctuated slightly from 1992 to 1994, in1995, web clamps in seat belt systemsdropped considerably and has remainedon the low side.

Passenger Side: The proportion ofpassenger seat belts with web clampsreached a high (35 percent) in 1994. In1995, web clamps in seat belt systemsdropped significantly and has remainedon the low side.


0

20

40

60

80

100

PE

RC

EN

T

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR

1 2 3 4 or more

Number of Sensors, 1990-1998Definition: Sensors are devices that aredesigned to initiate air bag inflation uponcrash impact.

Discussion:The chart shows a trend towards a lowernumber of air bag sensors in vehicles.Until 1996, more than half the vehicles inthe fleet had 3 or more sensors. In 1998,approximately 44 percent of the vehicleshad just one sensor. The proportion ofvehicles having two air bag sensors hasalso grown in recent years.

E1 (SENSOR INFORMATION) Air Bag Characteristics in Light Motor Vehicles A-43

0

20

40

60

80

100

PE

RC

EN

T

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR

CRUSH ZONE & OCCUP COMP ENGINE COMP & OCCUP COMP

CRUSH ZONE OCCUPANT COMPARTMENT

Location of Sensors, 1990-1998 Definition: Crash Sensors are typicallylocated in the:(a) Crush Zone which is approximatelythe front two feet of the vehicle;(b) Engine Compartment;(c) Occupant Compartment which isusually the tunnel or the console betweenthe two front seats; or, (d) Air Bag Module (for all mechanicalsystems).

Discussion: The chart shows a trendtowards the sensors being located in theoccupant compartment. For the pastseveral years, sensors located in the crushzone and occupant compartment and in theengine and occupant compartments havebeen decreasing. The percentage ofsensors located in the crush zone only hasremained about the same since 1995.

E1 (SENSOR INFORMATION) Air Bag Characteristics in Light Motor Vehicles A-44

0

20

40

60

80

100

PE

RC

EN

T

1990 1991 1992 1993 1994 1995 1996 1997 1998MODEL YEAR

Electronic-Electromechnical Electromechanical

Mechanical Electronic

Type of Sensors, 1990-1998Definition: The type of sensors falls intofour broad categories:(a) Electronic-Electromechanical which is a combination of Electronic and Electromechanical sensors;(b) Electronic Sensors;(c) Electromechanical Sensors; and(d) Mechanical Sensors.

Discussion: Although electromechanical airbag sensors had been the predominantsensor for many years, such sensors havebegun to decrease. From 1995 to 1998, theproportion of sensors that are electronic orelectronic-electromechanical has doubled.In 1998, electronic and electronic-electromechanical sensors accounted forapproximately 73 percent of the sensortypes.

E1 SENSOR INFORMATION Air Bag Characteristics in Light Motor Vehicles A-45

Appendix B. Manufacturer Information Request

[MANUFACTURER]

Re: Air bag technology in light passenger vehicles

Dear [Manufacturer]

As you are aware, the National Highway Traffic Safety Administration (NHTSA) plans to amend theautomatic restraint requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 208,“Occupant Crash Protection,” to require the installation of advanced air bags. NHTSA also continues toreview the progress of air bag technology and monitor the effects of its recent rulemaking action todepower air bags (62 FR 12960; March 19, 1997). In support of these various undertakings, NHTSAhereby requires [Manufacturer] to respond to the enclosed Information Request, issued pursuant to 15U.S.C. § 30117(a).

Subsection (a) of Section 30117 authorizes the Secretary of Transportation “to require that eachmanufacturer of a motor vehicle . . . provide technical information related to performance and safetyrequired to carry out [Chapter 301 of Title 49, United States Code].” These functions have beendelegated to NHTSA. 49CFR 1.50.

[Manufacturer] must respond to the enclosed Information Request, in accordance with the instructionscontained therein, by February 17, 1998. Failure to respond promptly and fully to this Information Requestcould subject [Manufacturer] to civil penalties pursuant to 49 U.S.C. § 30163.

NHTSA is aware that the holiday period is about to begin and that many manufacturers will be shut downfor some or all of that period. The agency has taken this fact into consideration in setting the 60-daydeadline for responding to this Information Request.

If you have any technical questions concerning this Information Request, please contact Mr. James R.Hackney, Director, Office of Crashworthiness, at (202) 366-1740. If you have any legal questionsconcerning this Information Request, please contact Mr. J. Edward Glancy of the Office of Chief Counselat (202) 366-2992.

Sincerely

/s/ James R. Hackney for

L. Robert SheltonAssociate Administrator For Safety Performance Standards

Enclosure

B-2

INFORMATION REQUEST

Re: Air Bag Technology in Light Passenger Vehicles

To: [Manufacturer]

I. Instructions

A. Each specification in this Information Request must be answered separately and fully, in writing. Above each answer, the text of the applicable specification must be provided.

B. The information provided in response to this Information Request must be derived from any andall information which is known to, or in the possession of [Manufacturer] . [Manufacturer] is notrequired to conduct any tests or physical measurements to respond to the specifications in thisInformation Request. However, [Manufacturer] is required to perform any calculations oranalyses necessary to derive responses to the specifications in this Information Request fromdocuments or other data already in {[Manufacturer’s]’ possession.

C. All documents furnished in response to this Information Request must be marked with the numberof the specification to which they respond. If [Manufacturer] cannot respond to any specificationor portion thereof, please state the reason why it is unable to do so.

D. If [Manufacturer] changed product configurations or suppliers during the course of a particularmodel year, state the effective date of any such change and answer all applicable specificationsseparately for each such configuration or supplier.

E. All measurements furnished in response to the specifications in this Information Request shall bestated in metric units.

F. Unless otherwise specified, [Manufacturer] shall respond to the specifications of this InformationRequest by providing information with respect to both driver and right front passenger seatingpositions.

G. If [Manufacturer] withholds any requested information from its response to this InformationRequest because of attorney-client or any other privilege, or for any other reason, it must furnisha description of each document or item of information withheld, and state the basis for suchwithholding.

H. If [Manufacturer] claims that any of the information submitted in response to this InformationRequest constitutes confidential commercial material within the meaning of 5 U.S.C. § 552(b)(4),or is protected from disclosure pursuant to 18 U.S.C. § 1905, an affidavit must be provided insupport of each such claim, including a statement of the competitive harm that [Manufacturer]believes would occur if the information were released to the public.

I. [Manufacturer] must submit three copies of its response to this Information Request to this officeby February 17, 1998. If [Manufacturer] considers any portion of its response to be confidentialinformation, include that material in a separate enclosure marked “Confidential.” In addition,

B-3

[Manufacturer] must submit a copy of all such material to the Office of Chief Counsel (NCC-30),National Highway Traffic Safety Administration, 400 Seventh Street, SW, Washington, DC20590, and comply with all other requirements for the submission of confidential businessinformation stated in 49 CFR Part 512.

II. DefinitionsFor purposes of this Information Request, the following definitions apply:

A. “Air bag” means an inflatable restraint installed at the driver or front outboard passenger seatingposition to provide occupant protection in frontal crashes.

B. “Air bag module” means the portion of an air bag system that includes the folded air bag andinflator, but does not include the air bag cover.

C. “[Manufacturer]” means [Manufacturer], its divisions, subsidiaries, and joint ventures, and allofficers, employees, agents, contractors, and consultants, past or present, of these entities.

D. “Longitudinal vertical plane” means a vertical plane that is parallel to the longitudinal centerline ofthe vehicle.

E. “Passenger portion of the instrument panel” means that portion of the instrument panel defined bya forward projection of the widest portion of the Hybrid III dummy, as positioned at the frontoutboard passenger seating position for a Standard 208 barrier test.

F. “Plane A” means the plane tangent to the face of the steering wheel rim. For the purpose oflocating that plane, an adjustable steering wheel is positioned as specified for a Standard 208barrier test.

G. “Plane B” means the horizontal plane tangent to the uppermost surface of the passenger portionof the instrument panel.

H. “Plane C” means the transverse vertical plan that passes through the center point of thepassenger air bag cover.

I. “Plane D” means the transverse vertical plane tangent to the portion of the passenger air bagmodule closest to a normally seated front outboard passenger.

J. “Plane E” means the transverse vertical plane tangent to the rearmost portion of the passengerportion of the instrument panel.

K. “Plane F” means the transverse vertical plane that passes through the SRP for the driver position.

L. “Plane G” means the transverse vertical plane that passes through the SRP for the front outboardpassenger seating position.

M. “Plane H” means the horizontal plane that passes through the SRP for the front outboard

B-4

passenger seating position.

N. “Plane I” means the horizontal plane that passes through the center point of the passenger air bagmodule.

O. “Plane J” means the transverse vertical plane that passes through the center point on the surfaceof the driver air bag cover. For the purpose of locating that plane, an adjustable steering wheel ispositioned as specified for a Standard 208 barrier.

P. “Plane K” means the transverse vertical plane that passes through the maximum rearward pointthat the driver air bag reaches at any time during deployment. For the purpose of locating thatplane, an adjustable steering wheel is positioned as specified for Standard 208 barrier test.

Q. “Plane L” means the transverse vertical plane that passes through the maximum rearward pointthat the passenger air bag reaches at any time during deployment.

R. “Plane M” means the longitudinal vertical plane that passes through the centerline of the HybridIII dummy, as positioned at the driver position for a Standard 208 barrier test.

S. “Plane N” means the longitudinal vertical plane that passes through the centerline of the HybridIII dummy, as positioned at the front outboard passenger seating position for a Standard 208barrier test.

T. “Record” means any and all information maintained by [Manufacturer], either in hard copyformat or in electronic storage media.

U. “Seating Reference Point” or “SRF” has the meaning specified in 49 CFR Part 571.3.

V. “Standard 208,” means Federal Motor Vehicle Safety Standard No. 208, as in effect (withapplicable amendments) for vehicles manufactured during the model year covered by a response.

W. “Transverse vertical plane” means a vertical plane that is perpendicular to the longitudinalcenterline of the vehicle.

III. SpecificationsPlease provide the following information, by model year, for each vehicle make/model that[Manufacturer] manufactured in or imported into the United States, in model years 1990-1998:

A. Information about air bag location, mounting and deployment direction:

1. Location and type of mounting:

a. For driver air bags:

(1) State whether the air bag module is recessed, flush, or protruded from Plane A,relative to the driver.

B-5

(2) Provide the closest distance from Plane A to the portion of the air bag module closestto the driver;

(3) Indicate whether the air bag module is designed to move away from the occupant atthe time of deployment and, if so, how far.

b. For passenger air bags:

(1) State whether the air bag is mounted at the top, middle or bottom of the instrumentpanel. (If the mounting of the air bag cannot appropriately be described in thismanner, please explain why and provide a verbal description of the mounting.)

(2) For top-mounted air bags, provide the distance from Plane C to Plane E.

(3) For air bags other than top-mounted air bags, provide the distance between Plane Band plane I, and between Plane H and Plane I.

(4) Indicate whether the air bag module is designed to move away from the occupant attime of deployment and, if so, how far.

2. Direction of deployment (passenger air bags only):

a. State the primary initial gas flow vector as measured in degrees from a horizontal plane.

b. Describe the primary initial direction of deployment, e.g., vertical, horizontal or theapproximate number of degrees from a horizontal plane.

B. Information about air bag cover configuration and opening during deployment.

1. State the size of the opening, providing both the dimensions of the opening and the area of thesurface of the cover.

2. State the minimum breakout pressure.

3. State the mass of the cover.

4. Provide a verbal description and/or an illustration of the tear pattern.

C. Information about air bag system components.

1. Air baga. State the number of chambers

b. Provide a verbal description and/or an illustration of the fold pattern.

c. State the material of the bag and the total mass of that material.

d. State the inflation time, from initiation of inflation until full inflation.

B-6

e. State the volume of the fully inflated air bag.

f. State the number and the location of the tethers.

g. Driver air bag deployment distance:

(1) State the distance between Plane J and Plane K.

(2) State the distance between Plane F and Plane K, and indicate which plane is forwardof the other.

(3) State the maximum distance the air bag reaches, laterally on each side of Plane N, atany time during deployment.

h. Passenger air bag deployment distance:

(1) For top-mounted air bags, state the distance between Plane C and Plane L.

(2) For air bags other than top-mounted air bags, state the distance between Plane D andPlane L.

(3) For all passenger air bags, state the distance between Plane G and Plane L, andindicate which plane is forward of the other.

(4) For all passenger air bags, state the maximum distance the air bag reaches, laterallyon each side of Plane M, at any time during deployment.

2. Information about the inflator

a. State (answer yes or no to each) whether the inflator is (1) pyrotechnic, (2) compressedgas, or (3) hybrid, and specify the gas generant.

b. State the number of inflation stages.

c. Provide the following information with regard to inflator characteristics during a tank testto measure inflator performance.

(1) Tank volume.

(2) Initial absolute pressure in tank (pre-firing).

(3) Temperature (pre-firing).

(4) Tank pressure versus time.

d. Identify (name and address) the supplier of the inflator.

B-7

D. Information about the seat belts.

1. Describe the stiffness of the seat belts, i.e., the force/elongation characteristics.

2. State whether load limiters are present or absent. If present, state the load limiting forcelevel.

3. State whether there are pretensioners. If so, state the number and type of pretensioners usedand describe their location relative to the belt system.

4. State whether there is a web clamp.

E. Information about the crash sensors and crash sensor control logic.

1. State the number of sensors in each vehicle, and describe the location of each, e.g., occupantcompartment, firewall, or crush zone.

2. Describe the type of sensors used, i.e., electromechanical, electronic, or other. If other,please identify and describe.

3. Identify (name and address) the supplier(s) of the sensors.

4. Identify (name and address) the supplier of the algorithm.

5. State the engineering specifications provided to suppliers for development of the algorithm. Define the crash conditions and time-to-fire requirements used to develop the algorithm,including, at a minimum, the nominal deployment threshold for each crash condition; the no-fire point for each crash condition; and the all-fire point for each crash condition.

F. Other system elements.

1. State whether the system contains any of the following components:

a. weight sensor

b. buckle sensor

c. child seat sensor

d. seat position sensor

e. on/off switch

f. inflatable knee bolster

g. pre-crash sensor

2. Identify (name and address) the supplier of every component identified in response to

B-8

Specification F.1.

G. System performance evaluations

1. For each of the following tests, provide the test speeds, and the head, neck, chest, and femurresponses:

a. All belted/unbelted rigid barrier crash tests conducted to ensure compliance with Standard208.

b. All tests conducted to ensure compliance with the Standard 208 alternative sled test.

c. All belted/unbelted rigid barrier crash tests conducted under test procedures substantiallysimilar to those of Standard 208.

2. For each out-of-position (dummy) test, including but not limited to ISO tests and pendulumtests, state the test conditions and procedures and provide the head, neck, chest and femurresponses.

3. For each offset crash test, state the test conditions and procedures and provide the head,neck, chest, and femur responses.

C-1

Appendix C. Tank Test Vessel

D-1

Appendix D. Supporting Data for the Out-of-Position and Barrier Testing

Out-Of-Position Dummy Set Up

Driver Air Bag Tests: As shown in Figure D-1, Position 1 for the adult dummy places the chin justabove the air bag module; while Position 2 centers the sternum on the module. The Position 1 tests foradult dummies are intended to maximize loading to the head and neck, resulting in higher risk of neckinjuries. The Position 2 tests are intended to maximize loading to the chest, resulting in higher risk ofthoracic injuries.


Figure D-1. Dummy Positioning for Driver Side Out-of-Position Testing with 5th PercentileFemale Dummy.

D-2

Passenger Air Bag Tests: As shown in Figure D-2, Position 1 for the child dummy places the chestagainst the middle section of the dash, while Position 2 places the head between the middle and upperportions of the dash. The Position 1 tests for the child dummies are intended to maximize loading to thechest, resulting in higher risk of thoracic injuries. The Position 2 tests are intended to maximize loadingto the head and neck, resulting in higher risk of neck injuries.


Figure D-2. Dummy Positioning for Passenger Side Out-of-Position Testing with 6-Year-OldChild Dummy.

D-3

Out-Of-Position Test Data

Driver Air Bag Test Data

Table D-1. Results for Driver Side Out-of-Position Testing with 5th Percentile FemaleDummy--Position 1

Model 15 ms HIC SNPRM Nij Chest Acceleration(Gs)

Chest Deflection (mm)

IARV 700 1.00 60.0 53.0 96 Camry 70 0.71 16.3 19.5 96 Neon 69 2.12 28.4 29.6 96 Taurus 136 1.01 24.0 30.2 96 Explorer 85 2.79 25.0 27.6

96 Average 90 1.66 23.4 26.7

98 Accord N/A 1.28 15.0 18.6 98 Camry 30 1.30 15.1 19.4 98 Neon 32 1.77 23.6 26.3 98 Taurus 33 1.64 15.4 16.7 98 Explorer 16 1.23 14.3 18.6

98 Average 28 1.44 16.7 19.9

99 Saturn SL 28 0.27 20.2 26.2 99 Toyota PU Buck 107 1.16 22.0 22.5 99 Econoline Van 13 0.97 13.5 22.3 99 Acura RL 220 1.32 17.7 29.9 99 Expedition 8 0.98 11.1 19.9 99 Intrepid Buck 24 0.70 24.4 27.3

99 Average 67 0.90 18.2 24.7

D-4

Table D-2. Results for Driver Side Out-of-Position Testing with 5th Percentile FemaleDummy--Position 2

Model 15 ms HIC SNPRM Nij Chest Acceleration(Gs)

Chest Deflection (mm)

IARV 700 1.00 60.0 53.0 96 Camry 28 0.76 18.0 29.4 96 Neon 160 2.30 31.6 43.3 96 Taurus NA 1.14 20.9 1.7 96 Explorer 32 2.22 36.4 39.8

96 Average 73 1.60 26.7 28.5

98 Accord 60 0.68 26.2 45.1 98 Camry 28 0.82 31.7 32.9 98 Neon 25 0.56 34.1 34.4 98 Taurus 14 1.00 27.6 38.7 98 Explorer 8 1.08 14.0 22.3

98 Average 27 0.83 26.7 34.7

99 Econoline Van 8 0.29 24.9 33.0 99 Saturn SL 61 0.37 22.9 36.4 99 Toyota PU Buck 59 0.65 30.2 31.3 99 Intrepid Buck 10 0.57 40.0 47.3 99 Acura RL 40 0.62 26.4 29.0 99 Expedition 9 0.34 32.2 37.0

99 Average 31 0.47 29.4 35.7

D-5

Passenger Air Bag Test Data

Table D-3. Results for Passenger Side Out-of-Position Testing with 6-Year-Old ChildDummy--Position 1

Model Distance 15 ms HIC MaxNij Chest Acceleration (Gs) Chest Deflection (mm)

IARV 700 1.00 60.0 40.0

99 Acura RL 0 101 1.26 19.5 10.7

99 Acura RL 0 87 0.91 19.4 6.9

99 Intrepid 0 149 2.78 58.9 42.1

99 Econoline 0 428 2.66 50.3 45.1

99 Expedition 0 42 1.02 39.2 49.8

99 Saturn 0 35 0.89 23.1 44.2

99 Tacoma PU 0 145 3.31 17.9 21.9

Average 141 1.83 32.6 31.5

98 Accord 0 132 2.05 37.0 40.1

98 Camry 0 213 3.64 32.8 11.3

98 Caravan 0 493 3.30 30.7 50.6

98 Explorer 0 210 5.91 50.2 50.2

98 Neon 0 172 2.65 22.3 41.8

98 Taurus 0 1854 2.81 64.0 50.5

Average 512 3.39 39.5 40.7

96 Camry 0 1020 8.67 64.6 45.4

96 Caravan 0 1207 NA 82.9 50.0

96 Explorer 0 276 2.91 42.5 63.0

96 Explorer 0 278 3.58 37.5 60.2 96 Neon 0 377 3.13 35.7 43.8

96 Taurus 0 2471 3.69 53.8 28.0

Average 938 4.40 52.9 48.4

98 Accord 4 142 1.53 28.1 27.4

98 Camry 4 1436 1.27 38.4 7.5

98 Caravan 4 91 0.69 32.9 25.2

98 Explorer 4 16 0.40 16.7 35.2

98 Neon 4 176 2.39 28.0 21.6

98 Taurus 4 1431 2.21 32.5 15.1

Average 549 1.42 29.4 22.0

96 Camry 4 1131 6.22 54.8 38.6 96 Caravan 4 697 1.36 50.9 49.6

96 Explorer 4 300 2.62 34.0 41.7

96 Explorer 4 375 1.67 54.0 53.0

96 Neon 4 236 3.19 27.5 30.2

96 Taurus 4 525 2.09 18.4 9.9

Average 544 2.86 39.9 37.2



IARV 700 1.00 60.0 40.0

D-6

98 Accord 8 66 0.92 16.0 19.7

98 Camry 8 395 2.31 28.1 30.4

98 Caravan 8 77 0.87 30.0 13.2

98 Explorer 8 73 0.86 20.2 11.9

98 Neon 8 495 0.70 16.2 10.0

98 Taurus 8 250 0.60 20.0 8.7

Average 226 1.04 21.8 15.7

96 Camry 8 656 3.09 42.1 N/A

96 Caravan 8 480 1.04 53.7 32.8

96 Explorer 8 111 0.86 25.6 40.3

96 Neon 8 873 2.35 25.2 24.1

96 Taurus 8 321 0.62 20.9 5.4

Average 488 1.59 33.5 25.7



IARV 700.0 1.00 60.0 40.0

99 Acura RL 0 101 0.83 17.7 3.0

99 Acura RL 0 113 0.94 16.0 9.0

99 Intrepid 0 627 3.27 68.8 39.7

99 Expedition 0 131 2.27 85.5 45.0

99 Econoline 0 429 2.22 65.0 34.3

99 Saturn 0 76 1.97 44.6 43.4

99 Tacoma PU 0 246 2.54 41.0 18.3

Average 246 2.01 48.4 27.5

D-7

0 100 200 300 400 500 Driver 15 msec HIC

MY99 IntrepidMY98 Voyager

MY98 Explorer 4LMY98 Camry

MY98 CherokeeMY98 Taurus

MY99 ExpeditionMY99 Tacoma

MY98 NeonMY99 Acura RL

MY99 Saturn SC1MY99 Econoline

MY98 Accord

Figure D-3. Driver Head Injury Criterion in 30 mph Unbelted Barrier Test.

30 MPH Rigid Barrier Testing

Driver Air Bag Test ResultsThe test results for the 50th percentile male driver dummy are found in Figures D-3 through D-7. Thedriver dummy in the MY 1999 Acura RL exceeded the maximum femur load requirement. This wasthe only IARV exceeded for the driver dummy in these tests. It should be noted that the injurymeasures for the chest displacement, head injury criterion, and neck injury criterion were below 90percent of the IARVs for each of the thirteen tested vehicles, with most below the 80 percent level. However, for chest Gs, two vehicles (i.e., the MY 1999 Dodge Intrepid and Acura RL) were within90 to 100 percent of the IARV.

D-8

10 20 30 40 50 60 Driver Chest Acceleration (Gs)

MY99 Acura RLMY99 Intrepid

MY99 EconolineMY98 Camry

MY98 VoyagerMY98 Taurus

MY99 ExpeditionMY98 Cherokee

MY98 Explorer 4LMY99 Tacoma

MY98 NeonMY99 Saturn SC1

MY98 Accord

Figure D-5. Driver Chest Acceleration in 30 mph Unbelted Barrier Test.

0 0.1 0.2 0.3 0.4 0.5 0.6 Driver Neck Injury Criteria

MY98 CherokeeMY99 Intrepid

MY98 VoyagerMY98 Neon

MY98 CamryMY99 ExpeditionMY99 Saturn SC1

MY98 TaurusMY99 Tacoma

MY99 EconolineMY98 Explorer 4L

MY99 Acura RLMY98 Accord

Figure D-4. Driver Neck Injury Criteria in 30 mph Unbelted Barrier Test.

D-9

0 4000 8000 12000 Driver Max Femur (N)

MY99 Acura RLMY99 TacomaMY99 IntrepidMY98 Accord

MY98 CherokeeMY98 Neon

MY98 VoyagerMY99 ExpeditionMY99 Econoline

MY98 CamryMY98 Explorer 4L

MY98 TaurusMY99 Saturn SC1

Figure D-7. Driver Maximum Femur Load in 30 mph Unbelted Barrier Test.

0 10 20 30 40 50 60 Driver Chest Deflection (mm)

MY98 VoyagerMY99 Tacoma

MY99 Saturn SC1MY98 Accord

MY99 IntrepidMY98 Cherokee

MY98 CamryMY99 Econoline

MY98 Explorer 4LMY99 Acura RL

MY99 ExpeditionMY98 Neon

MY98 Taurus

Figure D-6. Driver Chest Deflection in 30 mph Unbelted Barrier Test.

D-10

0 100 200 300 400 Pass 15 msec HIC

MY99 Acura RLMY98 Neon

MY98 VoyagerMY98 Camry

MY99 EconolineMY99 Intrepid

MY99 Saturn SC1MY98 Taurus

MY98 Explorer4LMY99 TacomaMY98 Accord

MY99 ExpeditionMY98 Cherokee

Figure D-8. Passenger Head Injury Criterion in 30 mph Unbelted Barrier Test.

Passenger Air Bag Test ResultsThe test results for the 50th percentile male passenger dummy are found in Figures D-8 through D-12. The passenger dummy in the MY 1998 Dodge Neon exceeded the IARV for chest Gs. This was theonly IARV exceeded for the passenger dummy in these tests. The injury measures for the chestdisplacement, head injury criterion, neck injury criterion, and femur load requirement were all below 90percent of the IARVs for each of the thirteen tested vehicles, again with most below the 80 percentlevel. However, for chest Gs, one vehicle (i.e., the MY 1999 Dodge Intrepid) was within 90 to100 percent of the IARV.

D-11

0 10 20 30 40 50 60 70 Pass Chest Acceleration (Gs)

MY98 NeonMY99 Intrepid

MY98 VoyagerMY99 Expedition

MY99 Acura RLMY98 Cherokee

MY98 TaurusMY98 Explorer4LMY99 Econoline

MY98 AccordMY99 Saturn SC1

MY99 TacomaMY98 Camry

Figure D-10. Passenger Chest Acceleration in 30 mph Unbelted Barrier Test.

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Pass Neck Injury Criteria

MY99 TacomaMY98 Neon

MY99 Saturn SC1MY98 Cherokee

MY98 VoyagerMY99 Acura RL

MY98 TaurusMY99 IntrepidMY98 Accord

MY99 EconolineMY99 ExpeditionMY98 Explorer4L

MY98 Camry

Figure D-9. Passenger Neck Injury Criteria in 30 mph Unbelted Barrier Test.

D-12

0 2000 4000 6000 8000 Pass Max Femur Load (N)

MY99 EconolineMY98 Voyager

MY98 CherokeeMY99 Intrepid

MY99 Acura RLMY99 Expedition

MY98 NeonMY99 Saturn SC1

MY99 TacomaMY98 Explorer4L

MY98 TaurusMY98 CamryMY98 Accord

Figure D-12. Passenger Maximum Femur Load in 30 mph Unbelted Barrier Test.

0 5 10 15 20 25 30 Pass Chest Deflection (mm)

MY99 IntrepidMY99 TacomaMY98 Voyager

MY99 ExpeditionMY98 Camry

MY98 NeonMY98 Accord

MY98 CherokeeMY99 Acura RL

MY98 Explorer4LMY99 Saturn SC1

MY98 TaurusMY99 Econoline

Figure D-11. Passenger Chest Deflection in 30 mph Unbelted Barrier Test.

D-13

Driver and Passenger 30 MPH Unbelted Rigid Barrier Test Data for MY 1998 and 1999 Vehicles

TABLE D-5. Unbelted Driver 50th Percentile Male.

Test # Chest GIARV = 60.0

Chest disp.IARV = 63.0

mm

HIC15IARV = 700

Nij ver. 9IARV = 1.0

Maximum Femur(N)

IARV = 10,008 N

30 mphRigid Barrier

MY99 Intrepid V3126 54.4 44.8 403 0.52 7,786 (R)

MY99 Tacoma V3128 43.7 48.4 176 0.33 8,839 (L)

MY99 Acura RL V3125 56.9 31.8 154 0.29 13,349 (L)

MY99 Saturn SC1 V3127 36.8 46.8 128 0.41 5,288 (R)

MY99 Econoline V3123 52.1 37.1 87 0.32 6,198 (L)

MY99 Expedition V3124 46.7 28.1 178 0.41 6,612 (R)

MY99 Average 48.4 39.5 207 0.38 8,012

MY98 Taurus V2832 47.2 21.9 181 0.38 5,556 (L)

MY98 Neon V2838 43.5 24.9 166 0.47 7,336 (R)

MY98 Camry V2837 51.8 38.1 231 0.45 6,115 (L)

MY98 Accord V2836 36.7 45.8 51 0.27 7,623 (R)

MY98 Explorer 4L V2839 44.4 32.3 272 0.30 6,033 (R)

MY98 Voyager V2773 48.0 54.7 350 0.47 7,309 (L)

MY98 Cherokee V2830 46.1 41.6 189 0.53 7,366 (L)

MY98 Average 45.4 37.0 205 0.41 6,763

D-14

Table D-6. Unbelted Passenger 50th Percentile Male .

Test # Chest GIARV = 60.0

Chest disp.(mm)

IARV = 63.0mm

HIC15IARV = 700

Nij ver. 9IARV 1.0

Maximum Femur(N)

IARV = 10,008 N

30 mphRigid Barrier

MY99 Intrepid V3126 54.1 25.7 223 0.40 7,890 (R)

MY99 Tacoma V3128 35.6 23.5 173 0.69 6,372 (R)

MY99 Acura RL V3125 49.8 11.6 367 0.44 7,676 (R)

MY99 Saturn SC1 V3127 40.2 9.2 200 0.50 6,374 (L)

MY99 Econoline V3123 45.8 7.3 226 0.35 8,039 (R)

MY99 Expedition V3124 51.0 19.6 132 0.34 6,975 (R)

MY99 Average 46.1 20.1 220 0.57 7,221

MY98 Taurus V2832 48.5 8.8 191 0.43 5,697 (L)

MY98 Neon V2838 61.4 16.0 297 0.59 6,606 (L)

MY98 Camry V2837 35.1 16.7 236 0.26 5,273 (R)

MY98 Accord V2836 45.0 13.1 160 0.39 4,677 (L)

MY98 Explorer4L V2839 48.2 10.3 186 0.31 6,341 (R)

MY98 Voyager V2773 53.4 20.3 249 0.48 8,025 (R)

MY98 Cherokee V2830 49.2 12.2 84 0.49 7,921 (R)

MY98 Average 48.7 13.9 200 0.46 6,363

E-1

Appendix E. SCI Supporting Data

SPECIAL CRASH INVESTIGATIONSNORMALIZED RATE OF SCI FATALITIES

FATAL DRIVERSConfirmed and Unconfirmed

September 1, 1999

Vehicle Model Year (in millions of vehicles)1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 Total

New RegisteredDriver Air Bag

EquippedVehicles

0.246 0.802 2.756 3.183 4.395 5.709 10.820

12.459

13.556

15.063

15.843

15.484

100.316

Vehicle Model YearCrash Date 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 Total Fatalities/ Million

Vehicle YearsSep 87 to Aug 88 0 0.000 87-88Sep 88 to Aug 89 0 0.000 88-89Sep 89 to Aug 90 1 1 0.263 89-90Sep 90 to Aug 91 1 3 4 0.572 90-91Sep 91 to Aug 92 1 1 0.088 91-92Sep 92 to Aug 93 1 2 1 4 0.234 92-93Sep 93 to Aug 94 1 2 1 3 7 0.251 93-94Sep 94 to Aug 95 3 1 4 0.099 94-95Sep 95 to Aug 96 1 1 2 1 5 0.093 95-96Sep 96 to Aug 97 1 1 3 5 5 3 18 0.261 96-97Sep 97 to Aug 98 1 2 1 1 2 4 3 1 15 0.177 97-98Sep 98 to Aug 99 1 1 1 2 5 0.050 98-99

Sep 99 to Aug2000Total 1 1 7 13 5 5 12 5 8 5 2 0 64

Fatalities/MillionVehicle Years

0.339 0.113 0.254 0.454 0.142 0.125 0.185 0.080 0.148 0.111 0.063 0.000

SPECIAL CRASH INVESTIGATIONSNORMALIZED RATE OF SCI FATALITIES

FATAL PASSENGERSConfirmed and Unconfirmed

September 1, 1999

Vehicle Model Year (in millions of vehicles)1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 Total

New RegisteredDriver Air Bag

Equipped Vehicles

0.000 0.090 0.120 0.080 0.510 1.820 5.590 9.200 9.840 13.270 15.010 15.010 70.540

Vehicle Model YearCrash Date 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 Total Fatalities/

MillionVehicleYears

TotalRFCSS

Fatals/Years/ Millions ofAir Bags

Fatals/Years/Millions of Air

Bags

Sep 87 to Aug 88 0 0.000 0 0.000 0.000 87-88

Sep 88 to Aug 89 0 0.000 0 0.000 0.000 88-89

Sep 89 to Aug 90 0 0.000 0 0.000 0.000 89-90

Sep 90 to Aug 91 0 0.000 0 0.000 0.000 90-91

Sep 91 to Aug 92 0 0.000 0 0.000 0.000 91-92

Sep 92 to Aug 93 1 1 0.382 0 0.000 0.382 92-93

Sep 93 to Aug 94 1 1 2 0.244 0 0.000 0.244 93-94

Sep 94 to Aug 95 1 2 5 8 0.460 1 0.057 0.402 94-95

Sep 95 to Aug 96 7 11 2 20 0.734 6 0.220 0.514 95-96

Sep 96 to Aug 97 4 13 9 6 32 0.790 6 0.148 0.642 96-97

Sep 97 to Aug 98 1 6 15 4 8 1 35 0.630 4 0.072 0.558 97-98

Sep 98 to Aug 99 1 6 1 3 2 2 15 0.213 0 0.000 0.213 98-99

Sep 99 to Aug 2000

Total 0 0 0 0 1 3 21 50 16 17 3 2 113 17


0.000 0.000 0.000 0.000 0.245 0.235 0.626 1.087 0.407 0.427 0.100 0.266

Total RFCSS 0 0 0 0 0 0 3 10 2 2 0 0 17


0.000 0.000 0.000 0.000 0.000 0.000 0.089 0.217 0.051 0.050 0.000 0.000


0.000 0.000 0.000 0.000 0.245 0.235 0.537 0.870 0.356 0.377 0.100 0.266

air bag technology in light passenger vehicles

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